Hypselostomatidae were originally introduced as a subfamily of Chondrinidae (Zilch 1959). In the same work, the subfamily Aulacospirinae Zilch, 1959 was erected, later synonymised by Schileyko (1998). Bouchet et al. (2017) treated Hypselostomatinae as a subfamily of Gastrocoptidae, while some authors used Hypselostomatidae (Páll-Gergely 2023a, b; Páll-Gergely and White 2023; Gojšina et al. 2022) Vertiginidae (Panha 1998a; Tanmuangpak and Dumrongrojwattana 2022) or Pupillidae (Burch and Panha 2002; Panha and Burch 2002a) to classify these representatives.

This genus is characterised by the combination of characters: i) a single lamella which is formed by a fusion of angular and parietal lamellae (it can appear bifid in some species, see below); ii) last whorl adnate to, or only very slightly detached from the penultimate; iii) shell surface pasty (dimpled) or finely spirally striated (never rough, sandpaper-like surface); iv) surface of apertural barriers smooth.

The following species possess some exceptions from the aforementioned combination of diagnostic characters for the genus: Anauchen kozari and Anauchen evanidus sp. nov. Both of them have rough (granulated) surfaces of the apertural barriers. Furthermore, A. kozari is much smaller (height 1.25 mm, width 1.3 mm) than all other congeners and has a palatal tubercle (typical for many Bensonella species). However, both species are retained in Anauchen for reasons listed under “Remarks” section for these species.

Thailand • 1 paratype; from the type locality; S. Panha leg.; SMF 3311444.

“Angthong National Park, Suratthani Province Thailand, 9°38'6"N, 99°41′16"E, 60 meters elevation…”.

This species is similar to many congeners, mostly based on the appearance of the apertural barriers. For differences, see under the following species: A. crassus sp. nov., A. huaykhakang, A. informis, A. obesus sp. nov., A. utaithaniensis and A. banmiensis.

Figure 10. 

Synoptic view of the species belonging to the genus Anauchen A A. angthongensis B A. banmiensis C A. crassus sp. nov. D A. eotvosi E A. evanidus sp. nov. F A. grandiportus sp. nov. G A. huaykhakang H A. informis informis I A. informis parcedentata J A. jokaii sp. nov. K A. kozari L A. messageri M A. obesus sp. nov. N A. picasso sp. nov. O A. rochebruni P A. turritus sp. nov. Q A. utaithaniensis.

Figure 11. 

Anauchen angthongensis, paratype (SMF 331444) A–D shell E, F enlarged apertural views.

This species is known only from the type locality.

Basal plica can be present or absent.

Thailand • 1 paratype; from the type locality; S. Panha leg.; CUMZ ver.44026.

“Chang Peuag Cave Mountain, Banmi District, Lopburi Province, 14°54'10"N, 100°30'8"E, 15 meters elevation” (Thailand).

This species differs from A. angthongensis by its shouldered whorls (not rounded as in the latter) and more enlarged last whorl. For differences from further similar species, see under A. crassus sp. nov., A. huaykhakang, A. informis, and A. utaithaniensis.

Figure 12. 

Anauchen banmiensis, paratype (CUMZ ver.44026) A–D shell E enlarged apertural view.

This species is known only from the type locality.

This species was also considered a member of Hypselostoma (Panha and Burch 2008) but given the fact that the shell shape and microsculpture resembles some Anauchen species (A. huaykhakang, A. utaithaniensis), we assign this species to the latter.

Holotype. Thailand • 1 empty shell (SH: 4.83 mm, SW: 3.54 mm); Ranong Province, south of Kra Buri, Tham Phra Kayang, southeastern part of the rock; 10°19.480'N, 98°45.933'E; 10 m a.s.l.; 22 Feb. 2015; A. Hunyadi leg.; CUMZ 14427. Paratypes. Thailand • 6 shells; same data as for holotype; coll. HA.

Thailand • 1 shell (damaged, not paratype); same data as for holotype; coll. HA.

Thailand, Ranong Province, south of Kra Buri, Tham Phra Kayang, southeastern part of the rock; 10°19.480'N, 98°45.933'E; 10 m a.s.l.

Anauchen species with finely dimpled (pasty) shell surface sculpture (no spiral striae), aperture adnate to last whorl, five strong apertural barriers (parietal, upper palatal, lower palatal, basal, columellar).

Figure 13. 

Anauchen crassus Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14427) A–D shell E, F enlarged apertural views.

Shell conical, consisting of 5.5–6 thick-walled, regularly increasing, rounded, convex whorls separated by a moderately deep suture. All shells from the type material are somewhat weathered but colouration is dark reddish brown to pinkish, opaque. Protoconch weathered so the surface sculpture is not clear, not spirally striated, consisting of ~ 1.5–1.75 whorls, glossy and slightly darker than the rest of the shell. Teleoconch pasty, very finely radially striated, with no sign of spiral striation. Last whorl adnate to the penultimate and slightly descending near the aperture (~ 10 ° compared to the shell axis) making the aperture profile prosocline to the shell axis. Peristome continuous, leaning on the penultimate whorl at the parietal side in form of a thick and distinct callus. It is slightly paler in colour than the rest of the shell, expanded (particularly on the parietal side where it forms a distinct callus) but not reflected. Aperture equipped with five strong, high, relatively short, and thick barriers (parietal, upper palatal, lower palatal, basal, and columellar). Parietal lamella is the strongest in the aperture, blade-like, slightly oblique, its outer part curved towards the palatal side and only almost reaching the expanding peristome. Upper palatal and lower palatal plicae are similar, the lower one being stronger, more slender, higher, and positioned slightly deeper in the aperture. Basal plica small and very short, knob-like. Columellar lamella thick and horizontal, situated in the middle of the columellar wall. None of these barriers reach the expanding peristome. Surface of all apertural barriers is smooth. Sinulus wide and parabolic (due to the position of angular lamella and upper palatal plica). Umbilicus open and deep but moderately wide, measuring ~ 1/6 of the shell width. Only the penultimate whorl is visible through the umbilicus. A very short and shallow groove is present on the last ~ ¼ of the body whorl, running from the peristome towards the umbilicus.

Figure 14. 

SEM imaging of Anauchen crassus Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14427) A protoconch surface B teleoconch surface C enlarged apertural view.

This species is similar to Anauchen angthongensis Panha, 2002 from which it can be distinguished by the lack of spiral striation and much wider umbilicus. Additionally, A. crassus sp. nov. has a shallower suture resulting in less convex whorls than in A. angthongensis. Anauchen informis Vermeulen, Phung & Truong, 2007 is also spirally striated, has narrower umbilicus and its whorls are more convex and less regularly increasing. Anauchen banmiensis is spirally striated and has a shouldered last whorl. For differences from A. obesus sp. nov., see under that species. Boysidia phatangensis Dumrongrojwattana & Assawawattagee, 2018 is more slender and has more whorls which are more convex, with deeper sutures. It usually also has an additional lamella in the columellar-parietal boundary region, which was not (but may be) present in A. crassus sp. nov. Boysidia phatangensis has a bifid lamella (concrescent angular and parietal) on the parietal side while A. crassus sp. nov. has one blade-like lamella. Basal plica in B. phatangensis is seemingly more closely positioned to columellar lamella, while that of A. crassus sp. nov. is somewhere between the lower palatal and columellar or even closer to the lower palatal. Infraparietal lamella is absent in the new species, but present in B. phatangensis. Lastly, the umbilicus of B. phatangensis is slightly more excentrical and wider than in A. crassus sp. nov.

(in mm, n = 5). SH = 4.83–5.39; SW = 3.54–4.04; AH = 2.15–2.24; 2.04–2.23.

The specific epithet refers to the thick (Lat. crassus) shell and apertural barriers of this species.

Only known from the type locality.

Holotype. Thailand-Myanmar • Shan-Siam boundary; Woodthorpe coll.; NHMUK 1903.7.1.1227.1. Paratypes. Thailand-Myanmar •; 6, same data as for holotype; NHMUK 1903.7.1.1227.2–7.

“Shan [Shan States, Myanmar]-Siam [Thailand] Boundary”.

This species differs from its congeners by the presence of weak barriers situated close to the peristome edge. All other congeners similar in shape (e.g., A. angthongensis, A. crassus sp. nov., A. informis), have barriers much stronger and higher. See also under H. iunior sp. nov.

Figure 15. 

Anauchen eotvosi, holotype (NHMUK 1903.7.1.1227.1) A–D shell E, F enlarged apertural views (from Páll-Gergely 2023b).

This species is known only from the imprecise type locality (Shan-Siam boundary).

Holotype. Thailand • 1 shell (SH: 2.57 mm, SW: 2.23 mm); Chanthaburi Province, 3.0 km W of Na Yai Am; 12.738°N, 101.881°E; 23 Apr. 1987; F.G. Thompson leg.; UF 530655. Paratypes. Thailand • 2 shells; same data as for holotype; CUMZ 14431 • 33 shells; same data as for holotype; UF 591355.

Thailand • 2 shells (1 damaged and 1 juvenile, not paratypes); same data as for holotype; UF 583732.

Thailand, Chanthaburi Province, 3.0 km W of Na Yai Am; 12.738°N, 101.881°E.

Anauchen with very slightly keeled last whorl (below the centre of the periphery) which is also detached from the penultimate. Teleoconch finely dimpled, pasty sculptured, with no spiral striae. Five or six apertural barriers present (parietal, infraparietal, upper palatal, lower palatal, basal and columellar), all strongly spiniferous.

Figure 16. 

Anauchen evanidus Gojšina & Páll-Gergely, sp. nov., holotype (UF 530655) A–D shell E, F enlarged apertural views.

Shell conical, brown, consisting of 4.5–5 convex whorls separated by a deep suture. Protoconch similar in colour as the rest of the shell, finely pitted, showing no spiralling pattern or spiral striae and consisting of 1.25–1.5 whorls. Teleoconch surface sculpture fine, pasty, without spiral striae and with several irregularly spaced whitish radial streaks which are most prominent on the last whorl. Last whorl convex but weakly keeled below the centre of the periphery, slightly detached from the penultimate near the aperture and very slightly ascending (below 5 ° compared to the shell axis). Peristome dirty white, expanded but not reflected. Aperture rounded, equally as wide as high. It is equipped with five or six simple apertural barriers (parietal, infraparietal, upper palatal, lower palatal, basal and columellar). Parietal lamella high and moderately strong, not reaching the expanding peristome. Upper and lower palatal plicae equally strong but the lower palatal is usually slightly higher. Basal plica present as a very weak, dot-like swelling situated halfway between the lower palatal plica and columellar lamella. The latter is sometimes almost as wide as long, provoking a rounded shape. The columellar wall of the aperture is weakly swollen around the columellar lamella. Infraparietal lamella present as a small swelling or completely absent. None of the apertural barriers are reaching the peristome (although the parietal lamella is the closest) and all are roughly spiniferous as well as the apertural surface. Sinulus wide and not strongly isolated from the rest of the aperture due to the relatively weak upper palatal plica. Umbilicus very narrow, measuring ~ 1/10 of the shell width. The umbilical groove is present running alongside it. This groove is the broadest near the peristome and regularly tapering towards the umbilicus, ending as a narrow canal at the last ~ ¼ of the body whorl.

Figure 17. 

SEM imaging of Anauchen evanidus Gojšina & Páll-Gergely, sp. nov., holotype (UF 530655) A protoconch surface B teleoconch surface C enlarged apertural view.

This species is the most similar to A. picasso sp. nov. and for differences, see under that species. The new species also bears some resemblance to Aulacospira pluangtong Panha & Burch, 2004, but the latter has less rounded whorls, more elongated umbilicus, smooth apertural barriers (not spiniferous) and it lacks the basal plica.

(in mm, n = 5). SW = 2.10–2.58; SH = 2.39–2.82; AH = 1.10–1.22; AW = 1.09–1.28.

The Latin word evanidus means vanishing, which refers to the quarrying of the type locality of this species.

This species is known only from the type locality.

Unlike congeners (except for A. kozari), this species has rough, spiniferous surface of the apertural barriers. It is retained in Anauchen because of the similar barrier arrangement to other species (e.g., A. angthongensis, A. crassus sp. nov., A. huaykhakang, A. obesus sp. nov.) and a single lamella on the parietal side.

Holotype. Laos • 1 empty shell (SH: 1.71 mm, SW: 1.92 mm); Khammouane Province, NE foot of Mount Pha Soung, caverns among slope boulders; 17°33.108'N, 104°52.301'E; 08 Feb. 2017; J. Grego leg.; CUMZ 14428.

Laos, Khammouane Province, NE foot of Mount Pha Soung, caverns among slope boulders; 17°33.108'N, 104°52.301'E.

Shell conical-ovoid, teleoconch radially and not spirally striated. Last whorl not detached from the penultimate and slightly descending. Aperture large, with seven weak barriers sitting on the peristome edge. Umbilicus narrow.

Shell brown, conical-ovoid with deep suture and bulging whorls. Whorls 3.25, rounded, regularly increasing. Protoconch consists of slightly > 1 whorl, finely pitted, its terminal part with ~ 12 equidistant spiral striae. Teleoconch with inconspicuous, irregular growth lines and finely dimpled (pasty), spiral striation absent. Last whorl rounded, adnate to the penultimate and slightly descending near the aperture (~ 15 ° compared to the shell axis), aperture slightly prosocline to shell axis in lateral view. Aperture conspicuously large to the shell size, parietal part adnate onto penultimate whorl forming a weak callus. Peristome slightly expanded but not reflected. Altogether seven apertural barriers could be found, all being blunt, knob-like, situated on peristome edge, their homologies with traditionally recognised barriers somewhat questionable. Parietal lamella is the largest, but still weak. Suprapalatal and upper palatal plicae situated close to each other, after some distance the next plica is the lower palatal. Lower palatal, basal, subcolumellar, and columellar situated in approximately equal distance from one another, gap between columellar and parietal is approximately as large as between parietal and the suprapalatal. There is a very slight thickening next to lower palatal plica, although it is questionable whether it would develop into a barrier. Surfaces of all apertural barriers are very finely granulated. Sinulus wide but low, not strongly isolated from the rest of the aperture. Umbilicus narrow, elongate, only shows body whorl.

Figure 18. 

Anauchen grandiportus Gojšina, Grego & Páll-Gergely, sp. nov., holotype (CUMZ 14428) A–D shell E enlarged protoconch view F, G enlarged view of the surface of the last whorl.

Anauchen grandiportus sp. nov. differs from all other species assigned to Anauchen on the basis of the seven small, marginal denticles and the greatly enlarged aperture.

(in mm, n = 1). SH = 1.92; SW = 1.71, AH = 0.96, AW = 0.87.

The specific epithet refers to the relatively large aperture when compared to the shell size.

This species is known only from the type locality.

Thailand • 1 paratype; from the type locality; 1997; S. Panha leg.; CUMZ ver. 038.

“Subkao, Huaykhakang Wildlife Sanctuary, Lansak District, Utaithani Province, 15°35'7"N, 99°18'8"E, 310 meters elevation…” (Thailand).

This species differs from A. angthongensis by the shouldered last whorl and concave-conical shell (due to the strongly enlarged last whorl). Anauchen banmiensis is much more strongly spirally striated, it last whorl is more distinctly shouldered and has a wider umbilicus with a deep groove inside it (absent in A. huaykhakang). For differences from A. utaithaniensis, see under that species.

Figure 19. 

Anauchen huaykhakang, paratype (CUMZ ver. 038) A–D shell E enlarged apertural view.

This species is known only from the type locality.

Vietnam • holotype; RMNH 108986.

Vietnam, Kien Giang Prov., Kien Luong, Hon Chong hill, doline along East flank.

This species is the most similar to A. angthongensis from which it differs by its more bulging whorls and more ovoid shell. A. banmiensis has a shouldered last whorl and stronger barriers.

Figure 20. 

Anauchen informis informis, holotype (RMNH.Moll.108986) A–F shell.

This subspecies is known only from the type locality.

Vietnam • holotype; RMNH 108987.

“Vietnam, Kien Giang prov., Kien Luong, Ba Tai hill”.

Similar to the nominotypical subspecies but with 1–3 barriers in the aperture (parietal always present, both palatals occasionally) and usually more whorls.

Figure 21. 

Anauchen informis parcedentata, holotype (RMNH.Moll.108987) A–F shell.

This subspecies is known only from the type locality.

Holotype. Vietnam • 1 shell (SH: 2.48 mm, SW: 2.31 mm); Nam Pia village, Hung Ba commune, Vi Xugen district, Ha Giang Province; 22°52.064'N, 105°4.814'E; 216 m a.s.l.; L.V. Hao, T. Ishibe, Y. Nakahara, K. Ohara, K. Okubo, J.U. Otani, V.P. Sang leg.; IEBR_LS_Anauchen.002H.

Vietnam, Nam Pia village, Hung Ba commune, Vi Xugen district, Ha Giang Province; 22°52.064'N, 105°4.814'E; 216 m a.s.l.

Anauchen species with conical shell, last whorl keeled at its base and slightly ascending near the aperture. Spiral striation absent. Aperture armed with four strong barriers, umbilicus narrow.

Shell conical, consisting of 5.5 regularly increasing, convex whorls separated by a deep suture. Colour light brown. There is not a clear boundary between the protoconch and the teleoconch due to the similar surface sculpture. Teleoconch pasty, very finely but irregularly radially striated, with no signs of spiral striation. Last whorl adnate to the penultimate and its last quarter slightly ascending near the aperture (~ 10° compared to the shell axis), making the aperture profile opisthocline to the shell axis. Last whorl with a blunt keel at its base, making the shell strongly triangular. Peristome continuous and thick, not very strongly expanded on the parietal side and not fully leaning on the penultimate whorl. It is slightly lighter in colour than the rest of the shell, not reflected. Sinulus rounded and well separated from the rest of the aperture. Aperture equipped with four strong but short barriers (parietal, upper palatal, lower palatal and columellar). Parietal lamella is the strongest in the aperture, blade-like. Upper palatal plica ~ 1/2 as strong as the parietal lamella and very slightly leaning towards the lower palatal plica. The latter is strong (only slightly weaker than the parietal) and moderately long. There is no basal plica. Columellar lamella thick and relatively low, situated in the middle of the columellar wall. All apertural barriers almost reach the expanding peristome. Surface of all apertural barriers is smooth. Umbilicus rounded, open but narrow, measuring ~ 1/11 of the shell width.

Figure 22. 

Anauchen jokaii Gojšina & Páll-Gergely, sp. nov., holotype (IEBR_LS_Anauchen.002H) A–D shell E, F enlarged apertural views.

See under A. messageri, A. rochebruni, A. pentadens and A. turritus sp. nov.

(in mm, n = 1). SH = 2.48; SW = 2.31; AH = 1.12; AW = 1.04.

This species is named after and dedicated to Mór Jókai (1825–1904), Hungarian novelist, dramatist, to commemorate the bicentenary of his birth. Jókai was interested in malacology, he had a large collection of (mostly marine) shells, and even published a satirical novel entitled “Novel of snails” (A csigák regénye).

Figure 23. 

SEM imaging of Anauchen jokaii Gojšina & Páll-Gergely, sp. nov., holotype (IEBR_LS_Anauchen.002H) A protoconch surface B teleoconch surface C enlarged apertural view.

Only known from the type locality.

Laos • holotype; Luang Prabang Province, Phou Xuang Mountain, ca 1.5 km NE of Ban Lak Sip, ca 5 km SE of Luang Prabang, under rocks and logs in old secondary forest under cliff; 19°851.6050'N, 10°2811.0810'E; 640 m a.s.l.; A. Abdou, I.V Muratov leg.; 24 Nov. 2006; MNHN-IM-2012-27269.

“Central Laos, Luang Prabang Province, Phou Xuang mountain, ca 1.5 km NE of Ban Lak Sip, ca 5 km SE of Luang Prabang, under rocks and logs in old secondary forest under cliff, 19°851.6050'N, 10°2811.0810'E, alt. 640 m”.

See under A. messageri.

This species is known only from the type locality.

This species is not a typical representative of its genus since it has a palatal tubercle frequently found in Bensonella and a granulated, rough surface of the apertural barriers frequently found in Hypselostoma. It is also the smallest of all Anauchen species. It is however retained in Anauchen for the following reasons: i) the arrangement of apertural barriers is highly reminiscent to those of A. messageri (see Páll-Gergely 2023a); ii) there is a single lamella on the parietal side; iii) last whorl adnate to the penultimate.

Figure 24. 

Anauchen kozari Páll-Gergely, 2023, holotype (MNHN-IM-2012-27269) (from Páll-Gergely 2023a) A–D shell.

Vietnam • 1 syntype of A. messageri; from the type locality; C. Messager leg.; MNHN-IM-2000-35159.

Vietnam • 2 shells; Cao Bang Province, Đeo Ma Phuc - Quang Uyen, left side of the road, rock crevice; 22°43.981'N, 106°20.333'E; 610 m a.s.l.; 14 Nov. 2011; A. Hunyadi leg.; coll. HA • 1 shell; Cao Bang Province, west of Quang Uyen, Phi Hao-Đau Tuyen; 22°42.188'N, 106°26.358'E; 500 m a.s.l.; 16. Nov 2011.; A. Hunyadi leg.; coll. HA • 8 shells; Lang Son Province, Huu Lung district, Minh Tien, 1400 m northeast of Cau Cheo Minh Tien; 21°34.024'N, 106°17.790'E; 30 m a.s.l.; 20 Feb. 2020; A. Hunyadi leg.; coll. HA • 13 shells; Lang Son Province, Huu Lung district, Huu Lien, 33.5 km from junction of roads 1B and 241 towards Ba Nang, left side of the road; 21°41.064'N, 106°22.871'E; 220 m a.s.l.;19 Feb. 2020; A. Hunyadi leg; coll. HA • 47 shells; Hoa Binh Province, Kim Boi district, Cao Duong, north of Đong Phu, 58 km from Nho Quan towards Hanoi on the Ho Chi Minh road; 20°42.591'N, 105°39.299'E; 10 m a.s.l.; 16 Feb. 2020; A. Hunyadi, H.V. Luong, J.U. Otani & S.V. Pham leg.; coll. HA • 1 shell; Thanh Hoa Province, Xa Ban Cong, Xom Sat; 20°22.897'N, 105°12.712'E; 60 m a.s.l.; 18. May 2012¸ A. Hunyadi leg.; coll. HA • 15 shells; Thanh Hoa Province, 9.8 km from centre of Ngoc Lac towards Lang Chanh, Ngoc Khe, left side of the road, 115 km; 20°7.192'N, 105°18.277'E; 13 Feb. 2020; A. Hunyadi, H.V. Luong, J.U. Otani & S.V. Pham leg.; coll. HA. China • 9 shells; Guangxi, Bose Shi, Leye Xian, Buliu He; 24°39.436'N, 106°43.245'E; 540 m a.s.l.; 08 Sept. 2013; A. Hunyadi leg.; coll. HA • 74 shells; Guangxi, Hechi Shi, Huanjiang Maonanzu Zizhixian, south of Mulun Guojiaji Ziran Baohuqu, Dongning; 25°05.970'N, 107°57.639'E; 530 m a.s.l.; 17 Sept. 2013, A. Hunyadi leg.; coll. HA • 3 shells; Guangxi, Laibin Shi, Xingbin Qu, Qidong Xiang; 24°00.512'N, 109°04.288'E; 150 m a.s.l.; 20 Sept. 2013; A. Hunyadi leg. • 2 shells; coll. HA • 2 shells; Guangxi, Hechi Shi, Du an Yaozu Zizhixian, Gaoling Xiang, 2 km west of Dingfucun; 24°03.197'N, 108°01.290'E; 320 m a.s.l.; 08 Oct. 2009; A. Hunyadi leg.; coll. HA • 171 shells; Guangxi, Hechi Shi, Bama Yaozu Zizhixian, southern edge of Jiaolecun; 24°07.045'N, 107°07.847'E; 590 m a.s.l.; 10 Sept. 2013; A. Hunyadi leg.; coll. HA • 24 shells; Guangxi, Hechi Shi, Nandan Xian, Lihuyaozu Xiang, southeast of Encun, rocks above the road; 25°04.163'N, 107°36.176'E; 630 m a.s.l.; 11 Sept. 2013; A. Hunyadi leg.; coll. HA • 10 shells; Guangxi, Guilin Shi, Guilin, Ludiyan Gongyuan, northeastern side of Moupanshan; 25°18.466'N, 110°15.862'E 145 m a.s.l.; 22 Sept. 2013; A. Hunyadi leg.; coll. HA • 14 shells; Guangxi, Chongzuo Shi, Longzhou Xian, Wude Xiang, vicinity of the junction towards Banxintun; 22°35.239'N, 106°46.096'E; 350 m a.s.l.; 24 Sept. 2013; A. Hunyadi leg.; coll. HA • 257 shells; Guangxi, Hechi Shi, Tiane Xian, Qimu Xiang, junction towards Lahaiyan, rock above the tomb; 24°51.130'N, 107°11.670'E; 600 m a.s.l.; 12 Sept. 2013; A. Hunyadi & M. Szekeres leg.; coll. HA • 5 shells; Guangxi, Guilin Shi, Yangshuo Xian, 5 km north of Xingpingzhen; 24°57.358'N, 110°31.857'E; 150 m a.s.l.; 15 Oct. 2009; A. Hunyadi leg.; coll. HA • 13 shells; Yueliangshan, Gaotianzhen, Yangshuoxian, Guangxi Zhuangzu Zizhiqu; 24°43.45'N, 110°28.32'E; K. Ohara, K. Okubo, J.U. Otani leg.; coll. PGB • 17 shells; Daxiaojingfengjingqu, Moyangzhen, Luodianxian, Guizhousheng; 25°33.73'N, 106°51.4333'E; 450 m a.s.l.; T. Ishibe, K. Okubo, J.U. Otani leg.; coll. PGB • 4 shells; near Hudiequan bridge, Gaotianzhen, Yangshuoxian, Guangxi Zhuangzu Zizhiqu; 24°44.45'N, 110°29.62'E; K. Ohara, K. Okubo, J.U. Otani leg.; coll. PGB.

“Haut-Tonkin” (Vietnam) (A. messageri); “Collected from the rocks, Mt. Nanshe [南蛇山], Yizhou District [宜州区], Hechi City [河池市], Guangxi Zhuang Autonomous Region, China. 24°30'22"N, 108°38'51"E, 270 m…” (A. whitteni).

Anauchen jokaii sp. nov. lacks the spiral striation and has its last whorl keeled at the base which separates it from A. messageri. Anauchen kozari is smaller, more depressed and has a palatal tubercle. See also under A. pentadens, A. rochebruni and A. turritus sp. nov.

This species has a wide distribution across Vietnam and China. Its northernmost known localities are situated in northern parts of Guangxi province (China) while the southernmost are from Thanh Hoa province (Vietnam).

We have observed high morphological variability within this species, particularly in the slenderness of the shell (Fig. 25). The basal plica is also occasionally present or sometimes absent. Anauchen whitteni Z.-Y. Chen, 2023 was described as a distinct species based on the absence of the basal plica. Since the basal plica was found here as a variable character and the species does not differ from A. messageri in any other characters, it is treated here as a junior synonym.

Figure 25. 

Anauchen messageri from different localities A China, Guangxi province, Hechi Shi (coll. HA) B China, Guangxi province, Bose Shi (coll. HA) C China, Guangxi province, Guilin Shi (coll. HA) D Vietnam, Tonkin, syntype (MNHN-IM-2000-35159 (from Páll-Gergely 2023a)).

Holotype. Thailand • 1 shell (SH: 2.94 mm, SW: 2.26 mm); Chiang Rai Province, Doi Tung, 50 metres before Wat Phra That Doi Tung, vicinity of the parking lot; 20°19.540'N, 99°49.987'E; 1350 m; 12 Feb. 2015; A. Hunyadi leg.; CUMZ 14429. Paratypes. Thailand • 15 shells; same data as for holotype; coll. HA • 10 shells; Chiang Rai Province, Doi Tung; 20°20′32″N, 99°50′21″E; 1320 m a.s.l.; 08. May 1988; F.G. Thompson leg.; locality code FGT-4417; UF 591335.

Thailand • 1 shell (juvenile, not paratype); Chiang Rai Province, Doi Tung; 20°20′32″N, 99°50′21″E; 1320 m a.s.l.; 08. May 1988; F.G. Thompson leg.; locality code FGT-4417; UF 583720.

Thailand, Chiang Rai Province, Doi Tung, 50 metres before Wat Phra That Doi Tung, vicinity of the parking lot; 20°19.540'N, 99°49.987'E; 1350 m.

Anauchen species with conical-ovoid, brown shell, pasty-like surface, last whorl adnate to the penultimate, five apertural barriers (parietal (angulo-parietal), upper palatal, lower palatal, weak basal, and columellar) and a narrow umbilicus.

Figure 26. 

Anauchen obesus Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14429) A–D shell E, F enlarged apertural views.

Shell conical-ovoid, brown, with 4.5–5 whorls separated by a deep suture. All whorls convex, bulging, rounded. Protoconch consists of ~ 1.5 whorls, finely pitted and with moderate spiral striae, the same colour as the rest of the shell. Teleoconch fine, pasty, with inconspicuous, irregular growth radial lines which are rarely more pronounced and in form of whitish streaks, most dense right behind the peristome. Spiral striation absent. Last whorl adnate to the penultimate and slightly descending (~ 25 ° compared to the shell axis) making the aperture profile prosocline to the shell axis. Peristome continuous, in form of a short and not much expanded callus leaning on the penultimate whorl at the parietal side. It is white, expanded but not reflected. Aperture equipped with five barriers (parietal (angulo-parietal), upper palatal, lower palatal, basal and columellar). Parietal (angulo-parietal) lamella almost fully reaching the expanded peristome edge. It is the largest in the aperture, sometimes single and sometimes with an additional smaller part, which is probably homologous with the angular lamella in other genera, pointed towards the palatal side. Upper palatal plica is weaker, lower, and less slender than the lower palatal. Lower palatal plica almost as strong as the angulo-parietal lamella. Basal plica in the form of inconspicuous knob, like a very slight swelling in the basal-columellar transition area. Columellar lamella almost reaching the expanded peristome, highest in its middle part and sloping towards the peristome edge where it becomes quite low. It is leaned towards the lower palatal plica. Surface of all apertural barriers is very finely granulated. Sinulus rounded, parabolic and well separated from the rest of the aperture. Umbilicus narrow, ~ 1/8 of the shell width, previous whorls not clearly visible through it. Umbilical groove absent.

Figure 27. 

SEM imaging of Anauchen obesus Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14429) A protoconch surface B teleoconch surface C enlarged apertural view.

Anauchen obesus sp. nov. is similar in shell shape to A. angthongensis, A. crassus sp. nov., A. eotvosi and A. informis. However, A. obesus sp. nov. can be separated by its smaller size and more globular shell.

(in mm, n = 4). SH = 2.71–3; SW = 1.95–2.26; AH = 1.1–1.27; AW = 1.06–1.23.

This species is named for its globose shell.

This species is known only from Doi Tung mountain.

Holotype. Thailand • 1 shell (SH: 2.95 mm, SW: 2.79 mm); Prachuap Khiri Khan Province, Khao Sam Roi Yot National Park, 3 km S of Park Entrance; 12.208°N, 99.993°E; 31 May 1987; F.G. Thompson leg.; UF 529706. Paratypes. Thailand • 1 shell; same data as for holotype; CUMZ 14430; 8 shells; same data as for holotype; UF 591339.

Thailand • 1 shell (juvenile/broken, not paratype); same data as for holotype; UF 583731.

Thailand, Prachuap Khiri Khan Province, Khao Sam Roi Yot National Park, 3 km S of Park Entrance; 12.208°N, 99.993°E.

Anauchen species with distinctly keeled last whorl (slightly below the centre of the periphery) which is also detached near the aperture and descending. Teleoconch spirally striated. Only four weak apertural barriers (parietal, upper palatal, lower palatal and columellar).

Figure 28. 

Anauchen picasso Gojšina & Páll-Gergely, sp. nov., holotype (UF 529706) A–D shell E, F enlarged apertural views.

Shell conical or very slightly conical-ovoid, brown, consisting of 4.5–5 whorls separated by a deep suture. Protoconch not much lighter than the rest of the shell, roughly pitted and terminally spirally striated, consisting of 1.25 whorls. Initial teleoconch whorls and the penultimate whorl slightly keeled. Fine spiral striation visible on the teleoconch as well, sometimes stronger near the protoconch (on initial teleoconch whorls), sometimes stronger on the last whorl. There are several irregularly spaced whitish radial streaks crossing the spiral striae. Last whorl enlarged and distinctly keeled slightly below the centre of the periphery. The keel is equally strong along its length but is getting lost right behind the peristome. Last whorl slightly detached from the penultimate near the aperture and slightly descending (~ 15 ° compared to the shell axis), thus making the aperture profile prosocline to the shell axis. Peristome is dirty white, very thick, expanded but not reflected. Aperture rounded, almost as high as wide. There are only four relatively weak apertural barriers (parietal, upper palatal, lower palatal and columellar). Of them, parietal lamella is the strongest and highest and reaching the expanding peristome. Both palatal plicae (upper and lower) are of similar appearance (but lower is usually slightly stronger than the upper), both weak (low and short) and tubercle-like. They are positioned close to each other, probably closer than in any other congener. Columellar lamella is weak and dot-like, usually not present as a distinct barrier but rather as a columellar thickening which is gradually lowering towards the expanding peristome. Surface of all apertural barriers is very finely granulated. Sinulus wide and not strongly isolated from the rest of the aperture due to the relatively weak upper palatal plica. Umbilicus very narrow, elongated and measuring 1/8–1/9 of the shell width. There is a strong umbilical groove running along the umbilicus. This groove is very wide near the peristome and then regularly tapering towards the umbilicus, finally terminating at the ~ ½ of the last whorl.

Figure 29. 

SEM imaging of Anauchen picasso Gojšina & Páll-Gergely, sp. nov., holotype (UF 529706) A protoconch surface B teleoconch surface C enlarged apertural view.

This species is different from other congeners by the strongly keeled last whorl below the centre of the periphery and the presence of four apertural barriers which are quite weak. It is most similar to A. evanidus sp. nov. but A. picasso sp. nov. has a more strongly keeled last whorl, weaker apertural barriers, and is spirally striated.

(in mm, n = 5). SH = 2.64–2.95; SW = 2.63–2.82; AH = 1.23–1.38; AW = 1.27–1.37.

This species looks like an Anauchen with rounded whorls painted in a Pablo Picasso style (i.e., resembling the art style known as Cubism). The specific epithet is to be used as a noun in apposition.

This species is known only from the type locality.

None.

“collected from Menglun Town (21°5'N, 100°6'E). Mengla County, Yunnan Province” (China).

This species differs from A. messageri by its less triangular shell, narrower umbilicus, absence of spiral striation, and presence of strong radial ribs on the last whorl (especially near the aperture). Anauchen pentadens differs from A. jokaii sp. nov. by its wider umbilicus, strong ribs on the last whorl, especially near the aperture, and a basal plica. Its last whorl is also regularly rounded, so the is shell less triangular. See also under A. rochebruni.

This species is known only from Yunnan Province, China.

According to the figures presented in Qian and Zhou (2014) and Chen et al. (2016), Chen (2023) considered it a member of Anauchen rather than Boysidia which we follow herein.

Vietnam • 1 syntype of A. rochebruni; from the type locality; collector unknown; MNHN-IM-2000-35156 • 1 syntype of B. gereti; from the type locality; C. Messager leg.; MNHN-IM-2000-35161.

Vietnam • 59 shells; Lang Son Province, Binh Gia, eastern edge of the village, Di Chi Keo Leng, rock wall; 21°56.302'N, 106°23.819'E; 375 m a.s.l.; 17 Feb. 2020; A. Hunyadi leg.; coll. HA • 55 shells; Lang Son Province, Bac Son district, Quinh Son, northern part of the village; 21°53.411'N, 106°20.944'E; 400 m a.s.l.; 18 Feb. 2020; A. Hunyadi leg.; coll. HA • 31 shells; Lang Son Province, Bac Son district, Quinh Son, northeastern part of the village, rock wall; 21°54.616'N, 106°20.542'E; 420 m a.s.l.; 18 Feb. 2020; A. Hunyadi leg.; coll. HA • 25 shells; Lang Son Province, Bac Son district, Long Dong, 3.8 km north from junction of roads 1B and 241; 21°56.728'N, 106°19.447'E; 390 m a.s.l.; 18 Feb. 2020; A. Hunyadi leg.; coll. HA • 4 shells; Lang Son, vicinity of Chua Tam Than; 21°51.353'N, 106°44.809'E; 265 m a.s.l.; 21 Feb. 2020; A. Hunyadi leg.; coll. HA • 1 shell; Ha Giang Province, Ha Giang 105.5 km - Đong Van, Xa Van Chai, left side of the road; 23°09.084'N, 105°10.774'E; 31. May 2012; A. Hunyadi leg.; coll. HA • 1 shell; Cao Bang Province, Đong Khe 3 km- Đeo Lung Phay, right side of the road; 22°24.223'N, 106°25.937'E; 390 m a.s.l.; 15 Nov. 2011, A. Hunyadi leg.; coll. HA • 1 shell; Cao Ban Province, Tring Khanh district, Canh Tien commune, Pac Rao village; 22°48.9408'N, 106°30.549'E; 544 m a.s.l.; L.V. Hao, T. Ishibe, Y. Nakahara, K. Ohara, K. Okubo, J.U. Otani, V.P. Sang leg.; coll. PGB. • 5 shells; Bac Kan Province, Na Ri district, 2 km S of Ban Dem, W slopes of a deep sinkhole covered with forest, in small cavern, in dense rainforest; 06 Apr. 2012; J. Grego, J. Šteffek leg.; coll. JG. China • 2 shells; Hunan; ex. coll. Mollendorff; SMF 42108 • 2 shells; Guangxi, Laibin Shi, Wuxuan Xian, Wuxuan Tongling Zhen str., north of Yagangcun, rocks; 23°29.827'N, 109°38.534'E; 100 m a.s.l.; 21 Sept. 2013; A. Hunyadi & M. Szekeres leg. • 17 shells; Guangxi, Hechi Shi, Bama Yaozu Zizhixian, southern edge of Jiaolecun; 24°07.045'N, 107°07.847'E; 590 m a.s.l.; 10 Sept. 2013; A. Hunyadi & M. Szekeres leg. • 1 shell; Guangxi, Yulin Shi, Xingye Xian, 2 km southeast frim Chenghuang, Lufengshan Scenic Area; 22°36.814'N, 109°45.457'E; 05 Oct. 2009; A. Hunyadi leg.; coll. HA • 147 shells; Guangxi, Chongzuo Shi, Longzhou Xian, north of Lenglei, Nonggang Nat. Res., northern edge; 22°29.161'N, 106°57.357'E; 220 m a.s.l.; 23 Sept. 2013; A. Hunyadi & M. Szekeres leg.; coll. HA • 2 shells; Hunan, coll. Moellendorff; SMF 42108; • 2 shells; Guangxi, Chongzuo Shi, 25 km southeast from the centre of Chongzuo, Chongzuo Shengtai Gongyuan, Langur Reserve; 22°16.293'N, 107°30.359'E; 220 m a.s.l.; 18 Oct. 2009; A. Hunyadi leg.; coll. HA • 51 shells; Guangxi, Chongzuo Shi, Longzhou Xian, Wude Xiang, Banxintun; 22°35.239'N, 106°46.096'E; 350 m a.s.l.; 24 Sept. 2013; A. Hunyadi leg.; coll. HA • 7 shells; Tao cun, Tong’anzhen, Pinglexian, Guangxi Zhuangzu Zizhiqu; 24°34.379'N, 110°56.022'E; 163 m a.s.l.; leg. K. Ohara, K. Okubo, J.U. Otani; coll. PGB.

Figure 30. 

Anauchen rochebruni from Hunan, China (SMF 42108) A–D shell.

“Tonkin” (Vietnam) (A. rochebruni); “Die nähere Heimat dieses Findelkindes von einer Windelschnecke ist nach obigem vorläufig nimmer wohl festzustellen; doch sicher im Innern des centralen China, in Hunan oder Hupé zu suchen.” [type locality questionable: Hunan or Hubei provinces, China] (A. angulinus).

Figure 31. 

Anauchen rochebruni from different localities A Vietnam, Cao Bang province (coll. HA) B China, Guangxi province (coll. HA) C Vietnam, Lang Son province (coll. HA) D Vietnam, Tonkin (syntype, MNHN-IM-2000-35156 (from Páll-Gergely 2023a)) E Vietnam, Tonkin, syntype of B. gereti (MNHN-IM-2000-35161 (from Páll-Gergely 2023a)).

The shell shape is most similar to A. messageri. However, it differs by the much weaker and fewer apertural barriers. Anauchen pentadens is less triangular, has a narrower umbilicus, lacks the spiral striation, has more apertural barriers which are also stronger and has strong ribs on the last whorl (especially near the aperture). Anauchen jokaii sp. nov. lacks the spiral striation and has its last whorl keeled at the base which separates it from A. rochebruni. The apertural barriers are also much weaker in A. rochebruni. See also under A. turritus sp. nov.

This species has a wide distribution extending from the Hunan province, China (type locality of A. angulinus) south to Lang Son province, Vietnam.

Anauchen angulinus is herein treated a synonym of this species because we observed no significant morphological differences between them.

There is intraspecific variation in the number of apertural barriers. There are usually three (parietal, palatal, columellar) but there can be as few as one (parietal). The last whorl can be more or less swollen, sometimes resulting in a strongly triangular shell shape.

Holotype. Vietnam • 1 shell (SH: 4.7 mm, SW: 3.2 mm); Thanh Hoa Province, 23.7 km south from centre of Ngoc Lac, Phuc Thinh, Lang Mieng, rock above the village; 19°55.869'N, 105°22.196'E; 65 m a.s.l.; 13 Feb. 2020; A. Hunyadi, H.V. Luong, J.U. Otani & S.V. Pham leg.; IEBR_LS_Anauchen.001H. Paratypes. Vietnam • 1 shell; same data as for holotype; CUMZ 14432 • 79 shells; same data as for holotype; coll. HA • 1 shell; same data as for holotype; coll. VG • 29 shells; Thanh Hoa Province, Nhur Thanh District, Hai Van, Hang Lo Cao Khang Chien, near cave; 19°37.079'N, 105°34.629'E; 22 m a.s.l.; 14 Feb. 2020; A. Hunyadi, H.V. Luong, J.U. Otani & S.V. Pham leg.; coll. HA.

Figure 32. 

Anauchen turritus Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (IEBR_LS_Anauchen.001H) (slender form) A–D shell E, F enlarged apertural views.

Vietnam • 13 shells (juveniles, not paratypes); same data as for holotype; coll. HA • 7 shells (juveniles/ damaged, not paratypes); Thanh Hoa Province, Nhur Thanh District, Hai Van, Hang Lo Cao Khang Chien, near cave; 19°37.079'N, 105°34.629'E; 22 m a.s.l.; 14 Feb. 2020; A. Hunyadi, H.V. Luong, J.U. Otani & S.V. Pham leg.; coll. HA.

Figure 33. 

SEM imaging of Anauchen turritus Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (IEBR_LS_Anauchen.001H) A protoconch surface B teleoconch surface C enlarged apertural view.

Vietnam, Thanh Hoa Province, 23.7 km south from centre of Ngoc Lac, Phuc Thinh, Lang Mieng, rock above the village; 19°55.869'N, 105°22.196'E; 65 m a.s.l.

Figure 34. 

Anauchen turritus Gojšina, Hunyadi & Páll-Gergely, sp. nov., paratype (coll. HA) (less slender form) A–D shell E enlarged apertural view.

Shell conical, consisting of 7.5–8 whorls. Teleoconch densely spirally striated. Last whorl adnate to the penultimate. Aperture equipped with four main barriers (parietal, upper palatal, lower palatal and columellar), supra-angular and additional two smaller barriers (basal and infraparietal).

Shell conical to weakly concave-conical, light brown-yellowish in colour, opaque. It is consisting of 7–8 regularly increasing whorls separated by a moderately deep suture. All whorls rounded, weakly convex. Protoconch lighter than the rest of the shell, slightly translucent, consisting of ~ 1.25–1.5 weakly spirally striated whorls. Teleoconch finely and densely spirally striated, especially on the last ~ 3 whorls. Spiral striae strong, irregularly spaced, curved, > 40 on the last whorl in a standard view. The space between two spiral striae ranges from the width of one to the width of two or even three spiral striae. These striae are occasionally crossed by a few radial whitish streaks, randomly positioned, but mostly present on the last and the penultimate whorl. Last whorl adnate to the penultimate, slightly ascending (~ 5 ° compared to the shell axis) and making the apertural profile slightly opisthocline to the shell axis. Peristome thick, the same colour as the rest of the shell, expanded and not reflected, very finely pitted. It is especially strongly expanded at the parietal side where it leans against the penultimate whorl and forms a thick callus. Aperture equipped with four main barriers (parietal, upper palatal, lower palatal, and columellar) and several smaller ones. Parietal lamella very strong and high, directed towards the lower palatal plica. Upper palatal plica very strong, developed equally as parietal lamella and slightly leaning towards the lower palatal plica. Parietal lamella and upper palatal plica are closely positioned, leaving a narrow spacing between them. Lower palatal plica is strong but weaker than the upper palatal, directed towards the embayment between columellar and parietal lamellae. Columellar lamella slightly oblique, directed towards the lower palatal plica and developed to the same extent. Between these main barriers, smaller number of minor ones are also observed. Supra-angular lamella present, small, and short, leaning towards the palatal wall. Interpalatal plica sometimes present, positioned rather obliquely. Subcolumellar lamella present as weak or absent. Basal plica present, short. A very slight thickening (swelling) like infraparietal lamella is present. This lamella is sometimes much stronger. Surface of all apertural barriers is finely granulated. Sinulus large, distinctly separated from the rest of the aperture due to the strong angulo-parietal lamella and upper palatal plica. Umbilicus narrow, measuring ~ 1/8 of the shell width and with almost perpendicular walls, not showing previous whorls.

This species is similar to various congeners such as A. rochebruni and A. messageri. However, it can be clearly separated from them by the separate lamellae on the parietal side (angular and parietal) and a generally more elongated shell with slightly more pronounced spiral threads. Anauchen turritus sp. nov. has spiral striation, more apertural barriers and a wider umbilicus than A. jokaii sp. nov. See also under H. annamiticum.

(in mm, n = 5). SH = 4.05–4.7; SW = 2.72–3.43; AH = 1.54–1.88; AW = 0.7–0.87.

This species is named after the tower-shaped (turreted) shell.

This species is known from two localities in Thanh Hoa Province, Vietnam.

We have observed significant intraspecific variability in this species. Shell can be high conical or conical (even weakly concave-conical). Some specimens (Fig. 32) have only six apertural barriers (supra-angular, parietal, columellar, basal, upper, and lower palatal) while others can have up to nine (including interpalatal, infraparietal and subcolumellar) (Fig. 34). Colouration is usually pale brown but colourless specimens also occur.

Thailand • holotype; 1997; S. Panha leg.; CUMZ ver. 041 • 2 paratypes; same data as for the holotype; SMF 331454.

Figure 35. 

Anauchen utaithaniensis, holotype (CUMZ ver. 041) A–D shell E, F enlarged apertural views.

“Patavi Mountain, Utaithani Province, 15°28'20"N, 99°45'17"E, 70 meters elevation…” (Thailand).

Figure 36. 

Anauchen utaithaniensis, paratype (SMF 331454) A–D shell E, F enlarged apertural views.

This species is most similar to A. huaykhakang and A. banmiensis but they are both spirally striated. Anauchen angthongensis is also spirally striated, has it last whorl regularly rounded and has a narrower umbilicus.

Figure 37. 

Distribution of species belonging to the genus Anauchen.

This species is known only from the type locality.

This species shows intra-populational variation of the angulo-parietal lamella. The angulo-parietal lamella of the holotype is bifid, while that of the paratype is almost completely fused.

We have divided the genus Bensonella in two species groups:

Group 1: Bensonella plicidens group which includes the majority of species. This group can be recognised by the combination of the following traits: i) a distinct palatal tubercle on the palatal lip (Fig. 9); ii) three barriers on the parietal side (angular, parietal, and infraparietal) (Fig. 9). Several species within the Bensonella plicidens group are not typical because they either lack a palatal tubercle or some of the three barriers on the parietal side (see remarks sections under those species).

Group 2: Bensonella wangviangensis species group includes only four species (B. wangviangensis, B. cardiostoma sp. nov., B. fracta sp. nov., and B. mitochondria sp. nov.). This group is recognised by the combination of the following traits: i) triangular-conical shell shape; ii) angular lamella as strong as the parietal or stronger, fully reaching the peristome; iii) palatal tubercle not typical but clearly represents a slightly discontinued part of the upper palatal plica (thus, it is of more lamella-like than tubercle-like). This part of the upper palatal plica is most probably homologous to the palatal tubercle found in other Bensonella species; iv) angular lamella and palatal tubercle are situated close together leaving a relatively narrow canal to the sinulus.

Figure 38. 

Distribution of A. messageri and A. rochebruni in China.

Holotype. Thailand • 1 shell (SH: 1.6 mm, SW: 1.3 mm); Chiang Rai Province, Doi Thung; 20°20.533'N, 99°50.350'E; 1320 m a.s.l.; 08 May 1988; F.G. Thompson leg. UF 347144. Paratypes. Thailand • 1 shell; same data as for holotype; CUMZ 14433 • 7 shells; same data as for holotype; UF 591340 • 1 shell; Chiang Rai Province, Doi Tung, 50 meters before Wat Phra That Doi Tung, vicinity of the parking lot; 20°19.563'N, 99°49.990'E; 1350 m a.s.l.; 12 Feb. 2015; A. Hunyadi leg.; coll. HA.

Thailand • 1 shell (juvenile, not paratype); same data as for holotype; UF 583721.

Thailand, Chiang Rai Province, Doi Thung; 20°20.533'N, 99°50.350'E; 1320 m a.s.l.

Bensonella species with a triangular-conical shell and strongly radially ribbed last whorl, especially near the aperture. Palatal plicae very strong. Umbilicus very narrow and elongated, dot-like.

Shell triangular, conical-ovoid, brown, consisting of 4.5–5 convex, rounded whorls separated by a moderately deep suture. Protoconch spirally striated (~ 12–15 spiral striae). The protoconch is initially light in colour and then regularly darkening towards the teleoconch. Teleoconch surface very finely spirally striated, striae much weaker than on the protoconch. On the penultimate whorl, relatively coarse, weak, radial growth lines are visible. They become more densely arranged and more prominent on the last whorl and especially near the aperture where they are rib-like (important for species identification!). They are crossed by very delicate and widely spaced spiral striae. Last whorl rounded and adnate to the penultimate. It is slightly ascending near the aperture (~ 20 ° compared to the shell axis), making the aperture profile weakly opisthocline. Peristome lighter than the rest of the shell, not much expanded and not reflected. There is a slight thickening behind the peristome in form of a cervical crest. Aperture equipped with 10–12 barriers. Parietal lamella is the strongest in the aperture, long and curved, sinuated in its middle part. Angular lamella long, thin, and continuous, reaching the peristome. There are four main palatal plicae (upper palatal, two interpalatals, and a lower palatal) and usually one smaller suprapalatal plica. Upper palatal plica strong, highest in its middle part and getting lower towards the peristome. Interpalatal plicae similar to each other and the upper palatal. Lower palatal plica is the strongest. There is a strong palatal tubercle sitting on the palatal lip of the peristome, sometimes of almost rectangular shape. Peristome is distinctly sinuated behind this tubercle. Below the palatal tubercle, there are usually one or two more tubercle-like swellings which are of unknown homology. Basal plica very weak and short. Columellar lamella almost horizontal and slightly weaker than upper and lower palatal plicae. Infraparietal lamella similar to the basal plica. Surface of all apertural barriers is finely granulated. Sinulus small, narrow, and distinctly separated from the rest of the aperture. Umbilicus very narrow, dot like and elongated.

Figure 39. 

Synoptic view of the species belonging to Bensonella plicidens group A B. alycaeus sp. nov. B B. boettgeri C B. cristatissima sp. nov. D B. dha sp. nov. E B. dracula sp. nov. F B. exploda sp. nov. G B. geminounca H B. hooki I B. karoensis J B. lakainguta K B. lophiodera L B. microdentata sp. nov. M B. mirabilis sp. nov. N B. montawa sp. nov. O B. multidentata sp. nov. P B. multihami Q B. nitens sp. nov. R B. nordsiecki S B. obex sp. nov. T B. pahpetensis U B. palatotridens V B. pangmapaensis W B. paviei X B. perfecta sp. nov. Y B. plicidens Z B. sericata sp. nov. AA B. serrata sp. nov. AB B. spelaea sp. nov. AC B. spinosa sp. nov. AD B. taiyaiorum AE B. tamphathai.

This species is different from other congeners by the strong, rib-like radial growth lines, especially on the last whorl near the aperture and very strong palatal plicae.

Figure 40. 

Bensonella alycaeus Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (UF 347144) A–D shell E, F enlarged apertural views.

(in mm, n = 5). SH = 1.55–1.78; SW = 1.3–1.57; AH = 0.65–0.80; AW = 0.65–0.70.

The specific epithet refers to the cyclophoroid subfamily Alycaeinae W. T. Blanford, 1864 due to the changing rib density on the last whorl. To be used as a noun in apposition.

Figure 41. 

SEM imaging of Bensonella alycaeus Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (UF 347144) A protoconch surface B teleoconch surface C enlarged apertural view.

This species is known only from the type locality.

Indonesia • lectotype of B. boettgeri; W Java; collector unknown; SMF 4616. Laos • 1 syntype of B. novemdentata; Pah Hia, Laos; collector unknown; MNHN-IM-2000-33881.

India • 6 shells; Nagaland, Naga hills; UF 00112290/5, UF 179749/1 • 3 shells; Eastern Naga Hills; W. Doherty leg.; NHMUK 1903.7.1.2853.

Java, Indonesia (B. boettgeri); “environs du village méo de Pah Hia, à 100 kilomètres au Sud de Xieng-Khouang, chef-lieu de la province du Tran Ninh, Laos” (probably refers to Ban Namthong, Longchaeng District, Xaisomboun Province, Laos, see Páll-Gergely et al. 2016) (B. novemdentata).

Even though there are no peculiarities regarding the apertural dentition of this species, it can be separated from all its congeners by the far most triangular, elongated shell and relatively shallow suture.

Figure 42. 

Bensonella boettgeri A–D lectotype (SMF 4616) E–H syntype of B. novemdentata (MNHN-IM-2000-33881).

This species is described from Java, Indonesia, but is also known from its synonym (B. novemdentata) in Laos. It has also been found in E India.

Figure 43. 

Bensonella boettgeri from Naga hills, India (NHMUK 1903.7.1.2853) A–D shell E–G enlarged apertural views.

Boysidia novemdentata was described from northeastern Laos, > 2800 km from the type locality of B. boettgeri. However, these two species are virtually identical in shell morphology. See the discussion section.

Holotype. Myanmar • 1 shell (SH: 1.77 mm, SW: 1.51 mm); Shan State, Taunggyi, mountainside above Aye Say Tee, Dragon Cave; 20°47.489'N, 97°3.036'E; 1380 m a.s.l.; 08 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; CUMZ 14434. Paratypes. Myanmar • 95 shells; same data as for holotype; coll. HA • 1 shell; same data as for holotype; coll. VG • 27 shells Shan State, west-southwest from Taunggyi, Montawa cave; 20°45.282'N, 97°1.057'E; 1260 m a.s.l.; 05 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; coll. HA • 10 shells; Shan State, Hopong centre ca 22 km towards Namsang, Hkoche, near Htem Sann Cave; 20°49.084'N, 97°20.119'E; 1240 m a.s.l.; 06 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; coll. HA.

Myanmar • 4 shells (3 juveniles and 1 broken, not paratypes); same data as for holotype; coll. HA.

Myanmar Shan State, Taunggyi, mountainside above Aye Say Tee, Dragon Cave; 20°47.489'N, 97°3.036'E; 1380 m a.s.l.

A small Bensonella species with fine, finely dimpled teleoconch sculpture, rounded last whorl adnate to the penultimate, and a strong, sharp cervical crest right behind the expanding peristome. Palatal plicae long and equally developed; umbilicus very narrow to almost closed.

Figure 44. 

Bensonella cristatissima Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14434) A–D shell E, F enlarged apertural views.

Shell triangular, slightly conical-ovoid, brownish or yellowish, weakly glossy. It is consisting of 4.5–5 regularly increasing, convex, rounded whorls separated by a deep suture. Protoconch consisting of ~ 1.5 coarsely spirally striated whorls. There are ~ 13 spiral striae on the protoconch and they are more densely arranged at the bottom of the whorl. Teleoconch surface finely dimpled (pasty) and with not numerous, weak radial growth lines. Spiral striae present initially on the teleoconch but getting lost so that the surface remains finely pasty-like or a very weak spiralling pattern might be visible (only on SEM images). Last whorl rounded, adnate to the penultimate. Right behind the peristome, there is a strong, thick, sharp, white cervical crest which is wider than the peristome and even visible behind it in the apertural view. Peristome thick and expanded but not reflected. Aperture equipped with numerous barriers, four of which are particularly strong (angular, parietal, infraparietal, and columellar), and situated closer to the peristome edge. Parietal lamella is the strongest and highest in the aperture. Angular lamella much longer than the parietal, very slender but continuous. Its inner and outer parts are higher than its middle part. Columellar lamella similar in length to the parietal only slightly weaker. This lamella is almost horizontal but sometimes slightly curved towards the palatal plicae. Infraparietal lamella is roughly half as strong as the parietal. Palatal plicae equidistant, all of equal height and length, altogether four (one upper palatal, two interpalatals, and a lower palatal). They are all high at their inner parts and then regularly lowering and tapering towards their outer parts. Palatal tubercle moderately strong or absent. Basal plica present, the same length as the palatals or slightly shorter. Surface of all apertural barriers is finely granulated. Sinulus small and narrow (resembling a comma sign), distinctly separated from the rest of the aperture. Umbilicus very narrow (measuring ~ 1/10 of the shell width) or even dot-like, almost closed.

Figure 45. 

SEM imaging of Bensonella cristatissima Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14434) A protoconch surface B surface of the last whorl C apertural view.

See under B. dha sp. nov.

(in mm, n = 5). SH = 1.77–1.86; SW = 1.45–1.52; AH = 0.73–0.80; AW = 0.63–0.76.

This species is named for the strong cervical crest which is the strongest among all the congeners.

This species in known from three localities in Shan State, Myanmar.

Holotype. Myanmar • 1 shell (SH: 1.9 mm, SW: 1.3 mm); Shan State, 5.8 km from centre of Hopong towards Namsang, left side of road #4, Hopong Spring Cave; 20°49.028'N, 97°13.469'E; 1110 m a.s.l.; 06 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; CUMZ 14435.

Paratypes. Myanmar • 34 shells; same data as for holotype; coll. HA • 1 shell; same data as for holotype; coll. VG.

Myanmar, Shan State, 5.8 km from centre of Hopong towards Namsang, left side of road #4, Hopong Spring Cave; 20°49.028'N, 97°13.469'E; 1110 m a.s.l.

Myanmar • 2 shells (juveniles, not paratypes); same data as for holotype; coll. HA • 4 shells; Shan State, 22 km from centre of Hopong towards Namsang, Htem Sann Cave; 20°49.0836'N, 97°20.1192'E; 1240 m a.s.l.; 06 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; coll. HA • 2 shells; Shan State, 13.5 km east-southeast from centre Kalaw, Myinmati Taung; 20°35.426'N, 96°36.794'E; 1350 m a.s.l.; 03 Oct. 2018; A. Hunyadi, K. Okubo & J. U. Otani leg.; coll. HA • 11 shells; Shan State, 7.4 km from centre of Hopong towards Namsang, 5 km north on road #4, Parpant cave; 20°50.963'N, 97°14.267'E; 1170 m a.s.l.; 06 Oct. 2018; A. Hunyadi, K. Okubo & J. U. Otani leg.; coll. HA • 4 shells; Shan State, Kalaw, Shwe Oo Min Paya; 20°37.2616'N, 96°33.4735'E; 1340 m a.s.l.; 02 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; coll. HA.

Bensonella species with conical shell which is not spirally striated. Apertural barriers numerous (angular, parietal, five palatals, one basal, one subcolumellar, one columellar, and one infraparietal) and with additional, strong palatal tubercle. Aperture well rounded.

Shell conical to conical-ovoid, light brownish and weakly glossy, consisting of 4.25–5.5 convex rounded whorls separated by a deep suture. Protoconch roughly pitted, sometimes with a spiralling pattern and consisting of ~ 1.5–1.75 whorls. Teleoconch with fine pasty structure, not spirally striated but with very fine radial growth lines. Last whorl adnate to the penultimate, aperture profile only slightly prosocline to the shell axis due to the slightly descending last whorl (~ 15 ° compared to the shell axis). Peristome slightly lighter than the rest of the shell, expanded but not reflected. It is particularly expanded on the parietal side where it forms a weak callus which is leaned on the penultimate whorl. Aperture equipped with moderately strong, numerous barriers. Parietal lamella moderately strong and high. Angular lamella longer but overall weaker than the parietal. It is higher in its inner part and regularly tapering towards the peristome, which is not reached. There are two or three very weak barriers inside the sinulus. Palatal wall equipped with five long barriers (suprapalatal, upper palatal, interpalatal, lower palatal, and infrapalatal) and a single strong palatal tubercle sitting on the edge of the palatal lip. Suprapalatal plica weak, not much stronger than the sinulus plicae. Upper palatal plica only slightly stronger than the suprapalatal. Interpalatal moderate. Lower palatal is the strongest among all the palatal plicae. Infrapalatal weak and shorter than others. Basal plica developed to the same extent as the infrapalatal. Subcolumellar lamella weak and short (nearly the same as the basal and infrapalatal). Columellar lamella strong as the lower palatal, almost horizontal. Infraparietal lamella moderate, ~ ½ as strong as the columellar. Surface of all apertural barriers is finely granulated. Sinulus small and not very distinctly separated from the rest of the aperture. Umbilicus very narrow, dot-like.

Figure 46. 

Bensonella dha Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14435).A–D shell E, F enlarged apertural views.

This species differs from B. cristatissima sp. nov. by the thinner peristome, less elongated apertural barriers and by the absence of a strong and sharp cervical crest.

(in mm, n = 13). SH = 1.56–2.02; SW = 1.14–1.53; AH = 0.64–0.78; AW = 0.64–0.73.

Named after the Burmese word for sword/knife (dha) referring to the blade-like anterior part of the palatal plicae. To be used as a noun in apposition.

This species is known from five localities in Shan State, Myanmar.

We have observed some intraspecific variability between the populations. The population from Shwe Oo Min Paya is the smallest and with the most ovoid shell. While the populations from Myinmati Taung and Parpant cave were the most triangular with slightly shallower sutures.

Figure 47. 

SEM imaging of Bensonella dha Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14435) A protoconch surface B surface of the last whorl C apertural view.

Holotype. Myanmar • 1 shell (SH: 2 mm, SW: 1.6 mm); Shan State, 22 km from centre of Hopong towards Namsang, Hkoche, near Htem Sann Cave; 20°49.084'N, 97°20.119'E; 1240 m a.s.l.; 06 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; CUMZ 14436. Paratypes. Myanmar • 16 shells; same data as for holotype; coll. HA.

Myanmar, Shan State, 22 km from centre of Hopong towards Namsang, Hkoche, near Htem Sann Cave; 20°49.084'N, 97°20.119'E; 1240 m a.s.l.

Myanmar • 3 shells; Shan State, Pinlaung centre SSW 11 km – Laneli Bridge, Nam Pam, near “Upper Spider Cave”; 20°2.114'N, 96°45.728'E; 1420 m a.s.l.; 04 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; coll. HA • 1 shell; Myanmar, Kayah State, Hpruso district, Maw Thi Do Village, entrance of Phruno river cave; 19°22.744'N, 97°2.570'E; 12 Feb. 2019; J. Grego leg.; coll. JG.

Bensonella species with triangular, conical-ovoid shell and rounded whorls devoid of spiral striation. There are two palatal tubercles in front of a strong and frontally concave transversal plica. A single, strong basal plica present.

Figure 48. 

Bensonella dracula Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14436) A–D shell E, F enlarged apertural views.

Shell triangular, conical-ovoid, consisting of 5–5.5 rounded, convex whorls separated by a deep suture. Protoconch consisting of ~ 1.25–1.5 roughly pitted whorls. Teleoconch devoid of spiral striation but with some fine radial growth lines, otherwise smooth, pasty. Last whorl adnate to penultimate. Aperture profile slightly opisthocline to the shell axis due to the very slightly ascending last whorl (~ 5 ° compared to the shell axis). In this view, a weak cervical crest could be observed behind the peristome. Peristome thick, expanded (especially on the parietal side where it forms a thick callus) but not reflected. Sinulus small and distinctly separated from the rest of the aperture. Aperture equipped with nine barriers (angular, parietal, upper palatal, transversal, two palatal tubercles, basal, columellar, and infraparietal). Parietal lamella very strong and high, curved and blade-like. Angular lamella much weaker and lower but longer, reaching the expanding peristome. Upper palatal plica moderate, higher in its middle parts. Transversal plica strong and with its frontal surface concave. In front of the transversal plica, there are two strong palatal tubercles. The upper one (usually present in all Bensonella species) is narrower and more acute. The lower palatal tubercle is wider and blunter. Basal plica present, short and ~ ½ as strong as the columellar lamella. The latter is strong, wide, and almost horizontal. Infraparietal lamella as strong as the basal plica. Surface of all apertural barriers is finely granulated. Umbilicus very narrow and slightly elongated, dot-like.

Figure 49. 

SEM imaging of Bensonella dracula Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14436) A protoconch surface B surface of the last whorl C apertural view.

See under B. nordsiecki, B. obex sp. nov. and B. taiyaiorum.

(in mm, n = 6). SH = 1.80–2.21; SW = 1.44–1.80; AH = 0.64–0.96; AW = 0.62–0.94.

Two strong palatal tubercles of this species resemble teeth of a vampire. The specific epithet refers to the iconic vampire, Count Dracula. To be used as a noun in apposition.

This species is known from the surroundings of Hopong and Pinlaung in Shan State, as well as Phruno river cave, Kayah State.

Specimens from Pinlaung (Shan) have a shorter transversal plica and have slightly more slender shells (Fig. 50). Specimen from the Phruno river cave in Kayah State has a more ovoid shell (Fig. 51).

Figure 50. 

Bensonella dracula Gojšina, Hunyadi & Páll-Gergely, sp. nov. from Pinlaung (coll. HA) A–D shell E, F enlarged apertural views.

Figure 51. 

Bensonella dracula Gojšina, Hunyadi & Páll-Gergely sp. nov. from Phruno river cave A–D shell E, F enlarged apertural views.

Holotype. Myanmar • 1 shell (SH: 1.8 mm, SW: 1.8 mm); Shan State, Pinlaung centre N 7.5 km, Tar Kge, near “Big Bang Cave”; 20°10.273'N, 96°47.442'E; 1540 m a.s.l.; 04 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; CUMZ 14446. Paratypes. Myanmar • 32 shells; same data as for holotype; coll. HA • 1 shell; same data as for holotype; coll. VG.

Myanmar • 3 shells (juveniles, not paratypes); same data as for holotype; coll. HA • 149 shells; Shan State, 5.7 km south-southwest from centre of Pinlaung, Wingabar Taung; 20°4.152'N, 96°46.232'E; 1510 m a.s.l.; 04 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; coll. HA.

Myanmar, Shan State, Pinlaung centre N 7.5 km, Tar Kge, near “Big Bang Cave”; 20°10.273'N, 96°47.442'E; 1540 m a.s.l.

Colourless Bensonella species with triangular conical-ovoid and spirally striated whorls. Last whorl slightly ascending near the aperture. Aperture equipped with eight strong barriers (angular, parietal, infraparietal, columellar, lower palatal, interpalatal, upper palatal, and a palatal tubercle). Umbilicus narrow but clearly wider than in majority of congeners.

Figure 52. 

Bensonella exploda Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14446) A–D shell E enlarged apertural view.

Shell strongly triangular, conical-ovoid, colourless, consisting of 5–5.5 regularly growing whorls separated by a moderately deep suture. All whorls rounded, convex. Protoconch-teleoconch boundary not clearly visible due to the similar surface sculpture and colouration. Protoconch with ten coarsely and equidistantly spaced spiral striae. Teleoconch also spirally striated but additionally with coarse radial growth lines which are roughly equidistant. Spacing between two spiral striae irregular, it ranges from the width of two to the width of four spiral striae. Last whorl flat at its base, adnate to the penultimate (but peristome not fully leaning on it), slightly ascending near the aperture (~ 5 ° compared to the shell axis) making the apertural profile weakly opisthocline to the shell axis. Peristome white, expanded but not reflected. Sinulus well-rounded and distinctly separated from the rest of the aperture. Aperture equipped with eight barriers (angular, parietal, infraparietal, columellar, lower palatal, interpalatal, upper palatal, and a palatal tubercle). All barriers relatively strong. Parietal lamella is the strongest in the aperture and wavy. Angular lamella is longer than the parietal and reaching closer to the expanding peristome. It is sinuated in its middle part. Infraparietal lamella ~ 1.5 × weaker than the columellar, short. Columellar lamella strong as the lower palatal or slightly stronger. It is positioned obliquely to the shell axis, directed towards the parietal lamella. Basal plica absent. Palatal plicae all equally strong and relatively short, upper palatal is usually the shortest. Interpalatal situated halfway between the upper and lower palatal. Palatal tubercle prominent, sitting on the palatal lip and roughly in the level with upper palatal plica. Surface of all apertural barriers is finely granulated. Umbilicus narrow (but clearly wider than in the majority of congeners), measuring ~ 1/8–1/9 of the shell width.

Figure 53. 

SEM imaging of Bensonella exploda Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14446) A protoconch surface B surface of the last whorl C apertural view.

This species differs from other congeners by the combination of the flat base of the last whorl, spirally striated whorls, and wider umbilicus.

(in mm, n = 5). SH = 1.77–1.89; SW = 1.58–1.71; AH = 0.71–0.77; AW = 0.66–0.68.

This species is named exploda after its type locality, the “Big Bang Cave”.

This species is known only from two localities in Shan State, Pinlaung.

The specimens from Wingabar Taung (Fig. 54) share all the characters with the specimens from Big Bang Cave but have weaker apertural barriers.

Figure 54. 

Bensonella exploda Gojšina, Hunyadi & Páll-Gergely, sp. nov. from Wingabar Taung, Shan State (coll. HA) A–D shell E enlarged apertural view.

China • 7 shells; Shaanxi province, Chang’an district, subtropical broadleaf forest, 1.2 km SE Xiaoqian Goukou village; 33°57.709'N, 108°45.868'E; 780 m a.s.l.; 08 July 2010; D.M. Palatov leg.; coll. JG • 4 shells; Hubei, Enshi Tujiazu Miaozu Zizhizhou, Enshi Shi, Taiyanghe Xian, Suobuya Shilin Jingqu, split rock; 30°34.663'N, 108°34.401'E; 975 m a.s.l.; 06 Nov. 2010; A. Hunyadi leg.; coll. HA • 1 shell; Hubei, Enshi Tujiazu Miaozu Zizhizhou, Badong Xian, E Badong, Bashan Senlin Gongyuan (near Xinglingzhen); 31°01.472'N, 110°25.284'E; 225 m; 03 Nov. 2011; A. Hunyadi leg.; coll. HA • 1 shell; Longfengyan, Hengjiangqiaoxiang, Jingzhoumiaozudongzuzizhixian, Hunansheng; 26°27.382'N, 109°34.650'E; 357 m a.s.l.; K. Ohara, K. Okubo, J. U. Otani leg.; coll. PGB • 5 shells; Sanjiaoyan. Zhilouzangzuxiang, Wenxian, Gansusheng Wenxian, Gansasheng; 32°53.180′N,, 104°24.672'E; 1646 m a.s.l.; Y. Nakahara, K. Okubo, J. U. Otani leg.; coll. PGB • 1 shell; along walking path below Cuying Lake (翠映湖), Qingchenghoushan (青城后山), Qingchengshanzhen (青城山镇), Dujiangyanshì (都江堰市), Chengdushì (成都市), Sìchuansheng (四川省); 30°56.2302'N, 103°28.7484'E; 1310 m a.s.l.; A. Hunyadi, T. Ishibe, K. Okubo, J. U. Otani, M. Szekeres leg.; coll. HA.

“Fengxian County (33°08'N, 106°05'E), Shaanxi Province” (China).

This species is known only from the type locality.

We could not locate the type specimens of this species. The original illustration of the holotype is inadequate. Based on the presence of the palatal tubercle, arrangement of apertural barriers, and shell shape, this species must belong to Bensonella (as already suggested by Páll-Gergely and White 2023). The specimens examined by us, collected in Shaanxi province (China) where the type locality of B. fengxianensis is located, may belong to this species, but this cannot be confirmed due to the absence of the type specimen. The same can be said for other samples in the nearby provinces (see Fig. 56).

Figure 55. 

Bensonella cf. fengxianensis from Shaanxi Province (coll. JG) A–D shell E–G enlarged views of the aperture.

Figure 56. 

Distribution map of Bensonella cf. fengxianensis.

Thailand • holotype; 27. May 1997, S. Panha, J. B. Burch, P. Dumrongrojwattana leg.; CUMZ 14366.

“Doi Chiang Dao, Chiang Dao Wildlife Sanctuary, Chiang Dao District, Chiang Mai Province, Thailand (19°22′046.3″N, 098°51′08.1″E, 2,015 m a.m.s.l.)”.

This species has a unique appearance of the infraparietal lamella which readily distinguishes it from all other congeners: it is consisting of two hooked parts pointing toward each other, outer (pointing inwards) and inner (pointing outwards).

Figure 57. 

Bensonella geminounca, holotype (CUMZ 14366) (from Jirapatrasilp et al. 2024) A–D shell E, F enlarged apertural view G enlarged view of the protoconch.

This species is known from different altitudes at the type locality (altitude range: 1650–2015 m).

India • holotype; Godwin-Austen coll.; NHMUK 20191114.

“…Cherrapunji…” (India).

See under B. lakainguta, B. montawa sp. nov., B. multihami, B. plicidens and B. spinosa sp. nov.

SE and SW Himalaya region.

After long-lasting taxonomic confusion, it has been shown that this species (hooked apertural barriers) is distinct from B. plicidens (blunt barriers) even though both “forms” were found mixed together in the same specimen lot (for details see Páll-Gergely and White 2023).

Figure 58. 

Bensonella hooki, holotype (NHMUK 20191114) A–D shell E–I enlarged apertural views (from Páll-Gergely and White 2023).

Indonesia • holotype; Jul 1996; W. Maassen leg.; RMNH.Moll.84438.

“N. Sumatra, Karo Highlands, Kuta Buluh, 40 km N of Brastagi, near the entrance of the cave Liangdehar in leaf litter at the foot of limestone rocks”.

See under B. plicidens.

This species is known only from the type locality.

This species is known only by a holotype (Maassen 1999).

Figure 59. 

Bensonella karoensis, holotype (RMNH.Moll.84438) A–F shell.

Figure 60. 

Distribution map of Bensonella boettgeri and B. karoensis.

Taiwan • holotype; 27 Aug. 1998, C-C. Hwang leg.; NMNS-7244-00.

Japan • 4 shells; limestone outcrop along forest rd., upstream Ugui-gawa, Aiga, Tsuchiyama-cho, Koka, Shiga; 34°57.9108'N, 136°22.185'E; 461 m a.s.l.; Kawase, J. U. Otani leg.; coll. PGB.

“TAIWAN: Mt. Zhibenzhushan, Wutai, Pingdung, 22°43'32.6"N, 120°52'50.2"E, alt. 2100 m”.

This species differs from B. hooki by its more triangular shell, more pointed apex, and parietal callus adnate to the penultimate whorl (not so in B. hooki, see Páll-Gergely and White 2023). For differences from B. montawa sp. nov., B. multihami, B. plicidens, and B. spinosa sp. nov. see under those species.

Figure 61. 

Bensonella lakainguta, holotype (NMNS-7244-00) A–D shell E–I enlarged apertural views (from Páll-Gergely and White 2023).

This species is well known from Japan as well as Taiwan and China (where it is known from a synonym, B. qingliangfengensis) (Fang et al. 2015; Páll-Gergely and White 2023).

This species was originally described as a subspecies of B. plicidens. Páll-Gergely and White (2023) have shown that it is distinct as it has hooked and not blunt apertural barriers, so. B. plicidens does not inhabit Japan and Taiwan where only B. lakainguta occurs.

Myanmar • holotype; collector unknown; CUMZ 14378.

Myanmar • 158 shells; Shan State, NNE of Kalaw, Osei Mountain Pagoda NW 150 m; 20°39.320'N, 96°34.927'E; 1565 m a.s.l.; 03 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; coll. HA • 181 shells; Shan State, Kalaw ESE 13.5 km, Myinmati Taung; 20°35.4264'N, 96°36.7938'E; 1350 m a.s.l.; 03 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg; coll. HA.

“Myinmati Cave, Kalaw Township, Taunggyi District, Shan State, Myanmar (20°35'24.6"N, 96°36'42.1"E; 1312 m a.s.l.)”.

The shell of this species is relatively large when compared to other geographically approximate congeners and the transversal palatal plica is rather weak and small. See under B. taiyaiorum.

This species is known from three localities in Kalaw.

This species lacks the palatal tubercle but is still clearly a member of Bensonella because of the triangular-conical shell shape and three barriers on the parietal side. In our specimens collected from Osei Mountain Pagoda (see above under “Material examined”), there is a transversal plica which is usually only partly merged, i.e., interpalatal and lower palatal plicae are clearly discernible (Fig. 63). Even though in the original description, this barrier is listed as a lower palatal, we believe that it is actually a transversal plica but just much weaker than in other congeners. Furthermore, Tongkerd et al. (2024: fig. 9C) shows a lower palatal plica that is wider than normal and positioned transversally indicating the fusion of the interpalatal and lower palatal plicae. Otherwise, our examined specimens fit perfectly in the description of B. lophiodera by all shell characters (size, colour, shape, surface sculpture, and apertural dentition).

Figure 62. 

Bensonella lophiodera, holotype (CUMZ 14378) (from Tongkerd et al. 2024) A–D shell E, F enlarged apertural views.

Figure 63. 

Bensonella lophiodera from Shan, Kalaw (Myanmar) (coll. HA) A–D shell E, F enlarged apertural views.

Holotype. Thailand • 1 shell (SH: 2 mm; SW: 1.5 mm); Lampang Province limestone dome at pass 11 km SSW of Ban Pang La; 18°27.9667'N, 99°48.3833'E; 610 m a.s.l.; 14. May 1988; F.G. Thompson leg.; UF 346912. Paratypes. Thailand • 1 shell; same data as for holotype; CUMZ14437 • 6 shells; same data as for holotype; UF 591333.

Figure 64. 

Bensonella microdentata Gojšina & Páll-Gergely, sp. nov., holotype (UF 346912) A–D shell E, F enlarged apertural views.

Thailand • 3 shells (juveniles, not paratypes); same data as the holotype; UF 583726.

Thailand, Lampang Province limestone dome at pass 11 km SSW of Ban Pang La; 18°27.9667'N, 99°48.3833'E; 610 m a.s.l.

Bensonella species with concave-conical, glossy shell that is spirally striated. Apertural barriers (usually eight or nine) and the surface around them prominently spiniferous.

Shell slightly concave-conical, glossy, light brownish, consisting of 5–5.5 convex and rounded whorls separated by a deep suture. Protoconch spirally striated, its boundary with the teleoconch not clear. There are ~ 12 widely spaced spiral striae on the protoconch and they are stronger at the base of the whorl. Teleoconch with relatively coarsely spaced, raised spiral striae (space between two striae equals the width of two or three striae) and with fine radial growth lines. On initial teleoconch whorls, radial lines are more densely arranged (similar to the spacing between the spiral striae) and are crossing the spiral striae forming a reticulated sculpture. Towards the last whorl, radial lines become coarser and the reticulated sculpture becomes weaker. Last whorl rounded, adnate to the penultimate, slightly descending near the aperture (~ 20 ° compared to the shell axis). Peristome whitish, expanded but not reflected. Sinulus parabolic due to the position of the angular lamella and the palatal tubercle. Aperture equipped with numerous barriers which have the typical Bensonella arrangement. These are: angular, parietal, upper palatal, interpalatal, lower palatal, palatal tubercle, basal, columellar, and infraparietal. Parietal lamella strong and moderately high, angular separated into inner and outer parts of almost equal height and width and a strong sinuation between them. Upper and interpalatal plicae positioned close together and almost equally as strong. Lower palatal plica situated some distance from other palatals and stronger than both of them. Palatal tubercle strong and sitting on the edge of the palatal lip. Basal plica weak, low, and short. Columellar lamella nearly as strong as the lower palatal. Infraparietal lamella only very slightly stronger than the basal plica. Surface of all apertural barriers is roughly spiniferous. Umbilicus narrow but relatively deep, measuring ~ 1/6 of the shell width.

Figure 65. 

SEM imaging of Bensonella microdentata Gojšina & Páll-Gergely, sp. nov., holotype (UF 346912) A protoconch surface B surface of the last whorl C apertural view.

This species is most similar to B. nitens (see under that species for differences). See also under B. paviei and B. tamphathai.

(in mm, n = 4). SH = 1.73–2; SW = 1.47–1.61; AH = 0.73–0.83; AW = 0.63–0.75.

This species is named for its small apertural barriers.

This species is known only from the type locality.

Holotype. Myanmar • 1 shell (SH: 2.05 mm, SW: 1.65 mm); Kayah State, Hpruso district, Maw Thi Do, road towards Han Li village, under bridge over Phruno river; 19°22.966'N, 97°2.153'E; 12 Feb. 2019; J. Grego leg.; CUMZ14438. Paratypes. Myanmar • 9 shells; same data as for holotype; coll. JG • 13 shells; Kayah state, Hpruso district, Maw Thi Do Village, entrance of Phruno river cave; 19°22.744'N, 97°2.570'E; 12 Feb. 2019; J. Grego leg.; coll. JG • 1 shell; same data as previous; coll. HA • 1 shell; same data as previous; coll. VG • 2 shells; Kayah State, Hpruso distr., Hoyar village, Kwar Yin cave; 19°18.096'N, 96°56.396'E; 13 Feb. 2019; J. Grego leg.; coll. JG • 1 shell; Kayah state, Hpruso district, Maw Thi Do, road towards Han Li village, rocks above bridge over Phruno river; 19°23.011'N, 97°2.108'E; 12 Feb. 2019; J. Grego leg.; coll. JG.

Myanmar • 5 shells (juveniles, not paratypes); same data as for holotype; coll. JG.

Myanmar, Kayah State, Hpruso district, Maw Thi Do, road towards Han Li village, under bridge over Phruno river; 19°22.966'N, 97°2.153'E.

Bensonella species with seven apertural barriers and a prominent hooked upper palatal plica which is pointing laterally (toward the palatal wall).

Shell triangular, slightly conical-ovoid, brownish, consisting of 5–5.5 whorls separated by a deep suture. All whorls rounded, convex, regularly increasing. Protoconch coarsely spirally striated, ~ 1.5 whorls. Spiral striae much more prominent terminally on the protoconch. Teleoconch with a fine pasty surface sculpture, without spiral striae but with fine radial growth lines. Last whorl rounded, adnate to the penultimate and straight near the aperture. Peristome brownish as the rest of the shell, expanded but not reflected. It is leaning on the penultimate whorl in form of a strong but not much expanded parietal callus. Palatal side of the peristome sinuated in its middle part, next to the palatal tubercle. Behind the expanding peristome, a weak cervical crest is present. Sinulus small and narrow, distinctly separated from the rest of the aperture. Aperture subrectangular, equipped with a smaller number of barriers (angular, parietal, upper palatal, lower palatal, columellar, infraparietal and palatal tubercle) than usual in Bensonella. Parietal lamella long but not reaching the expanding peristome. Angular lamella consisting of two separated parts: inner, which is slightly curved and positioned deeper in the aperture and outer part which is reaching the peristome edge. There is a strong sinuation between the inner and outer parts of the angular lamella. Palatal wall equipped with upper and lower palatal plica. Upper palatal plica of very peculiar appearance: it is very high with a hook positioned laterally (not pointing outside but directly to the palatal wall). Lower palatal plica nearly as strong as the parietal lamella. In front of the upper palatal plica, on the peristome edge, a strong palatal tubercle is observed. Columellar lamella rather weak. Above the columellar lamella, one additional infraparietal is present and it is nearly equally strong as the columellar. Surface of all apertural barriers is finely granulated. Umbilicus oblique (slightly elongated) and narrow, measuring ~ 1/6–1/7 of the shell width.

Figure 66. 

Bensonella mirabilis Gojšina, Grego & Páll-Gergely, sp. nov., holotype (CUMZ 14438) A–D shell E, F enlarged apertural views.

This species is easily distinguished from all other congeners by the presence of a laterally hooked upper palatal plica.

(in mm, n = 5). SH = 2.03–2.16; SW = 1.52–1.70; AH = 0.80–0.88; AW = 0.77–0.82

Named for the remarkable upper palatal plica (laterally hooked).

Figure 67. 

SEM imaging of Bensonella mirabilis Gojšina, Grego & Páll-Gergely, sp. nov., holotype (CUMZ 14438) A protoconch surface B surface of the last whorl C apertural view.

Known from four sampling sites in Kayah state, Hpruso district.

Holotype. Myanmar • 1 shell (SH: 1.8 mm, SW: 1.5 mm); Shan State, west-southwest from Taunggyi, Montawa cave; 20°45.282'N, 97°1.057'E; 1260 m a.s.l.; 05 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; CUMZ 14471. Paratypes. Myanmar • 30 shells; same data as for holotype; coll. HA.

Myanmar, Shan State, west-southwest from Taunggyi, Montawa cave; 20°45.282'N, 97°1.057'E; 1260 m a.s.l.

A Bensonella species with conical, pale yellowish shell. Aperture equipped with numerous barriers, all of which are in form of sharp hooks pointing outside. Parietal lamella with a blunt but long projection in front of the hook, almost reaching the expanding peristome. Umbilicus narrow, dot-like.

Figure 68. 

Bensonella montawa Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14471) A–D shell E enlarged protoconch view F, G enlarged views of the aperture H enlarged view of the last whorl surface.

Shell pale yellowish, triangular, conical ovoid, whorls 4–4.5, convex, rounded, rather regularly increasing. Protoconch consisting of ~ 1.25 whorls, showing spiralling pattern but with no clear spiral striae. Teleoconch with pasty surface, not spirally striated but with coarsely spaced, irregular radial growth lines. Last whorl adnate to the penultimate and slightly ascending near the aperture (~ 15–20 ° compared to the shell axis) making the aperture profile opisthocline to the shell axis. Peristome strongly expanded, not reflected. Aperture equipped with numerous barriers, all of which are in form of sharp hooks pointing outside the aperture. All barriers have low, slender projections situated in front of the hooks. A blunt, knob-like palatal tubercle sits anterior to the upper palatal plica on the peristome edge. Parietal lamella in form of a strong hook. A blunt, outer part of the parietal lamella is in form of a low, narrow, and blunt projection (situated in front of the hooked part) almost reaching the peristome edge. Angular lamella strong, consisting of inner and outer part separated by a strong sinuation. Inner part smaller, hooked, pointing towards the outer part which is larger but blunt. There are four weak barriers inside the sinulus. Upper palatal plica ~ 2 × weaker than the parietal and situated slightly above the palatal tubercle. First interpalatal plica as strong as the upper palatal, situated slightly below the palatal tubercle. Second interpalatal plica slightly weaker than the first. Lower palatal plica as strong as the first interpalatal and upper palatal. Infrapalatal plica small, as strong as the basal and subcolumellar. These three plicae are roughly equidistant. Above the subcolumellar, there is a clearly stronger columellar (similar in strength to the lower palatal plica) and one slightly stronger supracolumellar. Infraparietal lamella ~ 1/3 weaker than the parietal, with a similar (but shorter) projection in front of the hooked part. There are also some barrier-like swellings, although they never develop into a proper barrier. They can be e.g., between the upper palatal and first interpalatal plica, between the columellar and supracolumellar lamellae, between the supracolumellar and infraparietal lamellae, between the infraparietal and parietal lamellae. Surface of all apertural barriers is smooth. Sinulus parabolic, well separated from the rest of the aperture. Umbilicus very narrow, dot-like.

This species is very similar to B. hooki and B. lakainguta. Bensonella hooki is however more ovoid, reddish-brown, and does not have a slender projection in front of the parietal lamella. The latter also distinguishes the new species from B. lakainguta, which is also more triangular (i.e., pointed). See also under B. multihami.

(in mm, n = 3). SH = 1.8; SW = 1.4–1.6; AH = 0.69–0.77; AW = 0.74–0.79.

This species is named after its type locality, the Montawa Cave. The specific epithet is to be used as a noun in apposition.

This species is only known from the type locality.

Holotype. Thailand • 1 shell (SH: 2.40 mm, SW: 1.95 mm); Chiang Rai Province, Wat Phra That Tham Doi Khong Khao Meditation Centre, cave clay at the entrance of the cave, ca 6 km W of Chiang Rai; 19°54.771'N, 99°46.607'E; ca 420 m a.s. l.; Sept. 2017; A. Reischütz leg.; NHMW-MO-113729. Paratypes. Thailand • 1 shell; same data as for holotype; CUMZ 14439 • 29 shells; same data as for holotype; coll. REI • 1 shell; same data as for holotype; coll. VG • 41 shells; Chiang Rai Province, 5 km west from centre of Chiang Rai, vicinity of Wat Phra That Tham Doi Kong Khao; 19°54.820'N, 99°46.642'E; 420 m a.s.l.; 11 Feb. 2015; A. Hunyadi leg.; coll. HA.

Thailand • 3 shells (damaged/ juveniles, not paratypes); same data as for holotype; coll. REI • 2 shells; Chiang Rai Province, south-southwest from Mae Sai, vicinity of Wat Tham Pla; 20°19.723'N, 99°51.817'E; 400 m a.s.l.; 12 Feb. 2015; A. Hunyadi leg.; coll. HA • 22 shells; Chiang Rai Province, limestone Mtn. 6 km by road W of Ban Mae Suai; 19°38′55″N, 99°26′41″E; 650 m a.s.l.; 07. May 1988; F. G. Thompson leg.; locality code FGT-4415; UF 347105.

Figure 69. 

Bensonella multidentata Gojšina, A. Reischütz & Páll-Gergely, sp. nov., holotype (NHMW-MO-113729) A–D shell E enlarged protoconch view F, G enlarged views of the surface of the last whorl.

Thailand, Chiang Rai Province, Wat Phra That Tham Doi Khong Khao Meditation Centre, cave clay at the entrance of the cave, ca 6 km NW of Chiang Rai, 19°54.771'N, 99°46.607'E, ca 420 m a.s.l.

Figure 70. 

Bensonella multidentata Gojšina, A. Reischütz & Páll-Gergely, sp. nov., enlarged apertural views A, B holotype (NHMW-MO-113729) C paratype (coll. REI).

A Bensonella species with high triangular, concave-conical, densely spirally striated shell. Last whorl wide, rounded. Multiple (at least 10) well-developed apertural barriers.

Figure 71. 

Bensonella multidentata Gojšina, A. Reischütz & Páll-Gergely, sp. nov., paratype (coll. HA) A–D shell E, F enlarged apertural views.

Shell light brown, triangular, concave-conical, whorls 5–5.25, convex, rounded, rather regularly increasing. Protoconch consisting of ~ 1.25 whorls, its sculpture consists of ~ 10 equidistant spiral striae. Teleoconch finely, very densely spirally striated, and ornamented with a few, inconspicuous radial growth lines. Last whorl adnate to the penultimate and slightly to moderately descending near the aperture (~ range: 15–32 ° compared to the shell axis) making the aperture profile prosocline to the shell axis. Aperture subcircular, parietal part strongly extended towards penultimate whorl. Peristome strongly expanded, not reflected. Aperture with numerous and strong barriers. A blunt, knob-like palatal tubercle sits anterior to the upper palatal plica on the peristome edge. Sometimes, this tubercle is very weak or completely absent. All other barriers sit deeper, not reaching the peristome edge. Parietal lamella is the highest among all apertural barriers, long, almost straight, only slightly curved downwards. Angular lamella much lower and more slender than the parietal one. Upper palatal plica short and located slightly above the palatal tubercle. First interpalatal and lower palatal plicae equally strong. There is a smaller and shorter second interpalatal plica between them. Basal part of peristome with two or three low plicae (rarely one), they are situated next to each other, the one situated closer to the columellar lamella may be homologous with the subcolumellar lamella, and the other may be basal plicae. Columellar lamella is weaker than parietal and stronger than the palatal plicae, straight, pointing obliquely upwards. Supracolumellar and infraparietal denticles small, knob-like. Surface of all apertural barriers is finely granulated. Sinulus parabolic, wide, and not strongly separated from the rest of the aperture. Umbilicus wide, covers 1/3–1/4 of shell width.

Figure 72. 

Bensonella cf. multidentata Gojšina, A. Reischütz & Páll-Gergely, sp. nov., specimen found near Ban Mae Suai (UF 347105) A–D shell E enlarged view of the protoconch F enlarged view of the aperture G view of the last whorl surface sculpture.

See under B. nitens sp. nov., B. paviei, B. sericata sp. nov. and B. tamphathai.

(in mm, n = 5). SH = 2.40–2.51; SW = 1.81–1.97; AH = 0.82–0.94; AW = 0.85–0.95.

Named for the numerous barriers in the aperture.

This species is known from four localities in Chiang Rai province, Thailand.

The population found near Ban Mae Suai is characterised by shells that lack the palatal tubercle (or have a very slight swelling indicating its presence) and smaller number of apertural barriers (only one basal and one interpalatal). However, we do not intend to regard this population as distinct due to the lack of extensive material and the fact that main shell characters are shared with B. multidentata sp. nov. (shell shape, surface sculpture, umbilicus width and appearance of other barriers).

Thailand • holotype; 27. May 1997, S. Panha, J. B. Burch, P. Dumrongrojwattana leg.; CUMZ 14366.

“Doi Chiang Dao, Chiang Dao Wildlife Sanctuary, Chiang Dao District, Chiang Mai province, Thailand (19°22′046.3″N, 098°51′08.1″E, 2,015 m. a. m.s.l.)”

This species is strikingly similar to B. hooki, B. lakainguta, and B. montawa sp. nov. from which it differs in its blunt parietal lamella (hooked in former three)

This species is, apart from its type locality, known from one additional site: Doi Ang Khang (1400 m).

Figure 73. 

Bensonella multihami, holotype (CUMZ 14366) (from Tongkerd et al. 2024) A–D shell E enlarged apertural view F enlarged view of the protoconch.

Holotype. Thailand • 1 shell (SH: 1.91 mm; SW: 1.77 mm); Phrae Province, 11 km W of Phrae, on Road 1023 limestone knoll, leaf litter; 18°10′41″N, 100°4′14″E; 290 m a.s.l.; 16. May 1988; F.G. Thompson leg.; locality code FGT-4447, UF 346975. Paratypes. Thailand • 2 shells; same data as for holotype; CUMZ 14440 • 45 shells; same data as for holotype; UF 591334.

Thailand • 4 shells (juveniles, not paratypes); same data as for holotype; UF 583730.

Thailand, Phrae Province, 11 km W of Phrae, on Road 1023 limestone knoll, leaf litter; 18°10′41″N, 100°4′14″E; 290 m a.s.l.

Shell concave-conical, glossy, last whorl strongly enlarged. Teleoconch spirally striated. Last whorl adnate to the penultimate. Aperture equipped with numerous barriers, angular and columellar lamellae reaching the peristome. Umbilicus moderately wide.

Figure 74. 

Bensonella nitens Gojšina & Páll-Gergely, sp. nov., holotype (UF 346975) A–D shell E, F enlarged apertural views.

Shell concave-conical, brownish, consisting of 5–5.5 convex, rounded whorls separated by a deep suture. Last whorl much wider than all preceding ones, resulting in a concave-conical shell shape. Protoconch finely spirally striated initially, more prominently terminally. Its boundary with the teleoconch is not clearly visible due to the similar surface sculpture. Fine spiral striae present across the whole shell surface but quite difficult to observe on initial teleoconch whorls without SEM imaging. They are most clearly visible on the last whorl but still very fine. Spacing between the two spiral striae approximately measures the width of one or two striae. Radial growth lines extremely fine, irregularly spaced and not numerous, most clearly visible on the last and the penultimate whorls. Last whorl rounded, slightly descending (~ 10 ° compared to the shell axis), and adnate to the penultimate near the aperture. Peristome brownish, expanded but not reflected. On the parietal side of the aperture, the peristome leans on the penultimate whorl forming a thin parietal callus. Aperture equipped with numerous barriers (angular, parietal, upper palatal, two interpalatals, lower palatal, palatal tubercle, basal, columellar, and infraparietal). Parietal lamella is the strongest in the aperture, blade like and relatively high. Angular lamella discontinuous, consisting of weaker outer part (which is reaching the expanding peristome) and stronger (higher) inner part. Palatal plicae almost all equidistant. Upper palatal and first interpalatal equally strong, higher in their inner than in outer parts (but upper palatal can be weaker than the interpalatal). There is a strong, white palatal tubercle sitting on the palatal lip of the aperture, in front and between the upper palatal and interpalatal plica. Lower interpalatal plica is the weakest among them all. Lower palatal plica is the strongest among all the palatals. Sometimes, a very weak infrapalatal plica is also present and situated between the lower palatal and basal. All palatal plicae continue as slender projections towards the peristome. Basal plica small and usually the weakest in the aperture. Columellar lamella strong and oblique, leaned towards the parietal lamella. Infraparietal lamella slightly stronger than the basal plica. Surface of all apertural barriers is finely granulated. Sinulus parabolic due to the position of the angular lamella and the palatal tubercle. Umbilicus moderately wide, measuring ~ 1/5 of the shell width.

Figure 75. 

SEM imaging of Bensonella nitens Gojšina & Páll-Gergely, sp. nov., holotype (UF 346975) A protoconch surface B surface of the last whorl C apertural view.

This species is similar to Bensonella microdentata sp. nov., but the barriers are more numerous and not spiniferous, the umbilicus is wider and the last whorl is more enlarged. Bensonella nitens sp. nov. is smaller, glossier and has a weaker surface sculpture than B. multidentata sp. nov. The apertural barrier arrangement is strikingly similar in these two species but B. multidentata sp. nov. has stronger barriers and palatal plicae without slender projections towards the peristome. These projections are always present in B. nitens sp. nov. See also under B. sericata sp. nov. and B. tamphathai.

(in mm, n = 5). SH = 1.91–2.00; SW = 1.57–1.87; AH = 0.86–0.96; AW = 0.86–0.94.

The specific epithet refers to the shiny shell surface.

This species is known only from the type locality.

Thailand • holotype; 27. May 1997, S. Panha, J. B. Burch, P. Dumrongrojwattana leg.; CUMZ 14372.

“Doi Chiang Dao, Chiang Dao Wildlife Sanctuary, Chiang Dao District, Chiang Mai province, Thailand (19°22′046.3″N, 098°51′08.1″E, 2,015 m. a.m.s.l.)”.

This species is much more ovoid (less slender and triangular) than Bensonella dracula sp. nov. which also has a strong second palatal tubercle (very weak or absent in B. nordsiecki). The umbilicus is wider in B. dracula sp. nov. See also under B. obex sp. nov.

Figure 76. 

Bensonella nordsiecki, holotype (CUMZ 14372) (from Tongkerd et al. 2024) A–D shell E enlarged apertural view F enlarged view of the protoconch.

This species is known only from the type locality, with an altitude range from 605 m to 2015 m.

Holotype. Myanmar • 1 shell (SH: 1.8 mm, SW: 1.5 mm); Shan State, 5.7 km south-southwest from Pinlaung, Wingabar Taung; 20°4.152'N, 96°46.232'E; 1510 m a.s.l.; 04 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; CUMZ 14441. Paratypes. Myanmar • 32 shells; same data as for holotype; coll. HA.

Myanmar • 12 shells; Shan State, Pinlaung centre N 7.5 km, Tar Kge, near ”Big Bang Cave”; 20°10.273'N, 96°47.442'E; 1540 m a.s.l.; A. Hunyadi, K. Okubo & J.U. Otani leg.; coll. HA • 4 shells; Shan State, Pinlaung centre SSW 11 km – Laneli Bridge, Nam Pam, near “Upper Spider Cave”; 20°2.114'N, 96°45.728'E; 1420 m a.s.l.; 04 Oct. 2018; A. Hunyadi, K. Okubo & J.U. Otani leg.; coll. HA.

Myanmar, Shan State, 5.7 km south-southwest from Pinlaung, Wingabar Taung; 20°4.152'N, 96°46.232'E; 1510 m a.s.l.

Bensonella species with a pitted protoconch and conical-ovoid shell. Last whorl slightly ascending near the aperture. Peristome usually wrinkled due to several tubercles. Transversal plica strong and very weakly concave.

Figure 77. 

Bensonella obex Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14441) A–D shell E–F enlarged apertural views.

Shell conical-ovoid, consisting of 4.5–5 rounded, convex, regularly increasing whorls separated by a deep suture. Shell colour slightly weathered in the holotype but probably light brownish. Protoconch consisting of 1.75 whorls, finely pitted or sometimes spirally striated, especially terminally. Teleoconch finely pitted, with a pasty sculpture and without visible spiral striae but with coarsely and irregularly spaced radial growth lines. Last whorl enlarged, adnate to the penultimate and slightly ascending near the aperture (~ 20–25 ° compared to the shell axis). Aperture profile opisthocline to the shell axis. Peristome white and expanded (at columellar but especially at the parietal side where it forms a distinct callus) but not reflected. Aperture equipped with numerous barriers. Parietal lamella strong and high, almost reaching the expanding peristome. It sometimes has a heart-like appearance due to the distinct sinuation in the middle. Angular lamella weakly wavy, slightly weaker than the parietal but longer, reaching the expanding peristome. It also has a sinuation as in the parietal lamella but weaker. Upper palatal plica very short and moderately strong. Transversal plica strong, slightly concave on the front surface. A strong palatal tubercle is sitting in front and between the upper palatal and transversal plica. Below this tubercle, there are several more tubercle-like swellings which give the peristome a wrinkled appearance. Infrapalatal plica elongated and low. Basal plicae number ranging from one to four, similarly shaped as the infrapalatal plica. Subcolumellar lamella (if present) shares the same appearance as the former two. Columellar lamella moderate, ~ ½ as strong as the parietal. Supracolumellar lamella present but can be strong or quite weak. Infraparietal lamella slightly weaker than the columellar or even half as strong. Surface of all apertural barriers is finely granulated. Sinulus relatively narrow, small, and distinctly separated from the rest of the aperture. Umbilicus very narrow, measuring ~ 1/10 of the shell width, slightly elongated.

Figure 78. 

SEM imaging of Bensonella obex Gojšina, Hunyadi & Páll-Gergely, sp. nov., holotype (CUMZ 14441) A protoconch surface B surface of the last whorl C apertural view.

Bensonella nordsiecki has a smooth protoconch and more ovoid shell. The transversal plica in B. nordsiecki is without a concave frontal surface. Bensonella dracula sp. nov. is less ovoid, does not have a wrinkled peristome (but two palatal tubercles) and has a wider umbilicus.

(in mm, n = 10). SH = 1.42–1.8; SW = 1.36–1.5; AH = 0.61–0.81; AW = 0.63–0.70.

The specific epithet comes from a Latin word for a barricade (obex), which refers to the transversal palatal plica in the form of a barrier/obstacle. To be used as a noun in apposition.

This species is known from three localities around Pinlaung, Shan State.

Laos • 1 syntype; Pah Hia, Laos; collector unknown; MNHN-IM-2000-33880.

“environs du village méo de Pah Hia, à 100 kilomètres au Sud de Xieng-Khouang, chef-lieu de la province du Tran Ninh, Laos” (probably refers to Ban Namthong, Longchaeng District, Xaisomboun Province, Laos, see Páll-Gergely et al. 2016).

This species is unique due to the presence of one concrescent barrier on the parietal side in combination with the palatal tubercle typical for the genus Bensonella.

This species in known only from the type locality.

Bensonella pahpetensis is not a typical representative of its genus due to the concrescent angular and parietal lamellae. However, we have placed it in this genus because of the presence of the palatal tubercle as well as the triangular-conical shell shape.